Here are the steps:
1. Use ShowMiiWads to extract the file nand.bin from bootmii run
2. After extracting, go to the following folder:
a. If you use ACLGttC:
title/00010000/52555550/data
b. If you use ACCF:
title/00010000/52555545/data
3. Copy the four files inside that folder (banner.bin, rvforest.dat, wc24dl.vff, wc24pubk.mod)
to the newly created folder in step 4 below
4. Depending on which savegame wiibrew application that you use:
a. If you use Waninkoko's savegame installer and extractor applications, you need to create
a folder in your SD card: WIISAVES/RUUP or WIISAVES/RUUE (for ACLGttC or
for ACCF respectively)
b. If you use savegame manager application, you need to create a folder in your SD card:
savegames/0001000052555550 or savegames/0001000052555545 (for ACLGttC or
for ACCF respectively)
5. Run either Waninkoko's savegame installer or savegame manager wiibrew application to
reinstall that animal crossing savegame file to your Wii, and profit