> ...I would like to be able to edit my player in Animal Crossing City Folk to have a bald head
The game already has hats, glasses and wigs that you can use to change your appearance.
Also try the *limited* "Mii" feature (put your Mii face on your player - but you will lose it if you put on a hat or glasses). Also check non-hacking forums for advice.

Hacking note: More advanced texture editing is possible with runtime 'codes' but it is a lot of work and won't be visible to anyone else.
This is unlike the NPC texture mods that are visible to everyone including visitors and the changes go with them if the NPC leaves your town. You can't do that with the DS version.
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> And now they only say one thing over and over and over again
This is a common complaint with AC:CF. I think it is the way the game is written.
Check regular non-hacking BBSs, for example:
http://www.animalcrossingcommunity.c...sp?BoardID=152

Please compare to a non-hacked town, and if you can come up with a major behavior change, please email me the 2 gamesaves.
NOTE: the NPCs keep a database of relationships with human players. It is not being touched by NPC_Tool.