What did you use to desolder the chip? You should first give each pin a new coat of solder so the new solder mixes with the old, then use soldering braid and a solder sucker/pen thing to remove the freshly mixed solder. Then it should just be a matter of figuring out which pins have excess solder on them and gently rocking it out. Its a lot harder when you're trying to preserve the chip
I should be getting my CopyNES in the next month or so, my Powerpak Lite is lonely without a buddy. I am very excited to get some homebrew up and running on there, hopefully I'll have Tetris finished by the time it comes so I can test it out!
Congrats again.