try this:
Use the ALT version of ETool 3.13 (wrather than the flashcart version), just in case (I know the standard version has problems writing on Euro 2mbit and MKDS 2mbit saves)
1) run etool alone from the flash cart without the menu
2) when it starts eject the MK and insert animal crossing
3) refresh the id and then copy eeprom to sram
4) use npk and copy the sram save
5) use Etxtract from etools on the nsf file and use the map editor on the new file
7) now use ETcreate on the edited save

open NPK again, and select the ETool in the right hand side
9) restore the the output file you got from ETcreate
10) start etool and as before remove the MK and insert AC
11) refresh id and then copy sram to eeprom