If you haven't already performed this process, I would recommend getting (2) 1 GB sticks of memory and do the memory upgrade for the internal memory as well. You are going to have easy access to the "hidden" internal memory, so kill 2 birds with one stone!
I bought 2 sticks of Kingston PC2700 DDR SoDIMM - KVR333SO/1GR and now have 2 GB in my latop!
Test the memory first so you know it works before you get the laptop all back together! I put the 1GB sticks in my memory slot on the bottom of the laptop and ran Memtest86 for about 30 mins to check them one at a time. Then booted the laptop and used it for about an hour (opened a bunch of apps and just verified it all seemed stable) using each stick.
I have a 7422GX and opted to also upgrade the memory when I did the fix for the screen flicker (another fix you may want to consider while you are doing surgery).
I'm adding some comments to qhn's posted steps (
GHN's post (
http://www.notebookforums.com/thread172587.html 09-06-2006, 05:45 PM ) that may help you remove the palmrest. Sorry I didn't take pictures, I was in a hurry to get the screen flicker repaired and back to my sister before she headed back to college for her summer classes.
Also, I used a couple of pill boxes (the kind where you can prep your vitamin/medicine pills for a week / month at a time) to hold the screws as I took them out so I could easily remember the order to put them back. I also used scotch tape to label where the screws went (fold one end over so you have a "pull tab" to easily take the tape off later). Some of the screws did not want to leave their holes once I got them loose, so I just put a piece of scotch tape over the hole so they wouldn't fall out after I turned the laptop back over and get lost. Some are very small.
Also,
please take pictures, especially close ups of screw locations and components of interest. They can also be useful in putting things back when you reassemble things.
One last tip - the ribbon cables are held in by a simple locking mechanism, gently pry the sides of the connecter up on each side (about 1/16 to 1/32 of an inch) and the ribbon cable will be very easy to take out. I marked the right side of the ribbons with a dot from a red marker so I could remember the alignment. Make sure the connector is still "open" when you put the ribbon cable back in and then push the locking mechanism back down to hold the ribbon cable in place.
I used this as a reference guide;
http://emachines.fizi.ca/index.php/LCD_Disassembly
Here are the steps qhn posted; (my comments are from memory as I did this process about 10 days ago ....

)
this is a very rough guide, sorry that i did not take any pic when i was working on my modding (forum members please feel free to pitch in if i miss anything, or something is out of whack, since this is purely per memory)1. ac out, battery out, hold out the power button for 30 secs to fully discharge & getting rid of static)2. remove all screws in the bottom, mark their positions3. remove the ram from the slot if u have one, put the cover back4. remove wifi card, mark the antenna wires when removing it - leave the cover out - my wires were taped to the chasis and I pulled them loose. You will need to be able to pull the wires through the chassis when you take the palmrest off.5. remove the hard drive (there is another screw after u take the drive out - remove it6. turn the laptop over, use the guide above to remove the power strip and the lcd - follow this guide's steps up to figure 8 (http://emachines.fizi.ca/index.php/LCD_Disassembly)7. what u need is to remove the input inverter cable so that u can remove the heatsink. You don't need to remove the heatsink for your needs (or the flicker or memory upgrade), but you do need to remove the LCD wire harness by removing the tape from the heat sink, unplug the connector from the motherboard and the ground screw going into the heat sink hold-down post. Figure 2 of this guide shows(http://emachines.fizi.ca/index.php/LCD_Flicker_Repair shows what you need to remove (red Xs in the picture). Note: I did not do any modifications to the connectors discussed in this guide to resolve my flicker problem and I'm currently flicker free.8. to detach the lcd completedly, remove the cables connected to the optical frame, a 2 wire connectors (mark the colour position), the connector to the mobo - now u can slide the antenna cables thru the optical housing. There's a wire harness (or two?) on the right hand side. Remove them. Gently pull the connectors lose. There might be another ground screw for cable on the right side, too.8a. Remove the 2 screws holding the LCD panel to the chassis (one on the left and one on the right) and carefully lift the LCD panel free of the chassis. Put it aside and protect the LCD screen, I used a cotten towel.9. there r 2 screws along the upper part of the casing after u remove the lcd - remove them. Mine had 4 screws.10. remove the keyboard - careful with the ribbon,, do not force it out, there is a latch to keep it in place11. remove the plate underneath the keyboard (reference guide above) I used this guide (http://emachines.fizi.ca/index.php/LCD_Disassembly,
figure 7).11a. I removed the DVD drive by simply pushing it out from the inside. Just to give me some working room and to help make sure I didn't have any connections hiding in this area.12. now u can remove the upper casing, paying attention to the touchpad ribbon and be careful pulling the wi-fi cable through the chassis.13. You should now have easy access to the CMOS battery.Now that you are this close, upgrade the internal memory;14. There was a small metal cover (lower left corner) that had 3 screws that needed to be removed.15. There are 2 screws holding the PCMCIA slot assembly in place. Remove them and gently remove the PCMCIA slot assembly.16. You now have EASY access to the "hidden" memory slot17. Take the memory out and install the 1GB memoryReverse the above steps to reassemble the laptop.
Tips for fixing the flicker problem:
1) I made sure I had plenty of slack in the left side LCD harness by rerouting the LCD harness above the small heat sink. (see figure 8
http://emachines.fizi.ca/index.php/LCD_Disassembly).
2) I made sure the LCD harnesses were firmly seated and then hotglued the wires in place to reduce the stress on the connections and to keep them from working loose. My right side seemed like it slid about a 1/4 inch in and out.
3) I put a small amount of hot glue to hold the left LCD harness in the small black channel on the chassis right before it enters the LCD assembly and right after it enters the LCD assembly.
4) I put some hot glue to hold the right side LCD harness in place and made sure the wires laid flat.
My LCD Flicker has not occurred in the past 10 days.
Questions for others who have done the flicker fix;
1) Did you use any type of glue to put the rubber screw covers back in place on the LCD screen and if so, what kind?
2) Where is the LCD screen close switch? My laptop doesn't seem to be going into sleep mode or hibernate when I close the lid. I think I might have missed connecting a wire or knocked a switch out of alignment.......