There's detailed advice on opening remotes here...
http://www.hifi-remote.com/jp1/disassemble/
The way I do it is to use a very small screwdriver top pop open the first clip. I hold the remote upside down with the battery compartment side facing me, then I use the screwdriver to open the upper right hand corner.
Once the first clip is popped, I slide a plastic putty knife into the crack and slide it around the opening to pop the rest of the clips. You can get plastic putty knives from the hardware store for about $1. If you don't have one available, you can also use an old credit card (but be prepared to trash the card).
I solder in the 6-pin connector first, then I place the PCB back into the lower half of the remote casing (to hold it in place). I then place the EEPROM onto the U2 spot and hold it in place with tweezers. I have a long thin tip on my iron (which kinda looks like a sharpened pencil). I lay the tip down across pins 1 thru 4 soldering them all at once. This also serves to hold the chip in place while I individually solder pins 5 thru 8. Remember, it's OK for the solder to bleed between pins 1 thru 4, but not for pins 5 thru 8.
I then put in the batteries and lay the button sheet down on the PCB so I can work the buttons, and I do a 981 reset. If you get 2-short, 1-long blink, you need to go back and check your work, if you get 4-short blinks, all is good so far, now you just need to try a download to check the 6-pin connections. If that works, you're done, now you just need to re-assemble the remote.