This page will explain you how to get a NAND backup that works with SNEEK/UNEEK.
Method 1 - Generating using ModMii
1. Download ModMii and extract it to your desktop.
2. Click on ModMii.exe and type "I Agree" and hit enter when it opens.
4. Choose which System Menu version you would like to have ("4.2" or "4.3") and press enter.
5. Type "D" and press enter (unless you would like to use your own setting.txt in which case either choice will work)
6. Choose whether to download Wii channels:
~ Downloading a lot of files ~
8. ShowMiiWads will pop up, type "45e" and click OK.
Note: It may look like it crashed, but it didn't, just wait for it to finish.
9. After ModMii is done, your brand new NAND is built and in the ModMii folder on your desktop.
Method 2 - Extracting a Bootmii NAND dump
1. Dump your Wii NAND with Bootmii.
2. Place the nand.bin in a folder on your desktop
3. Open "ShowMiiWads"
4. Select "Tools" --> "Extract Bootmii Dump" and browse to the nand.bin.
6. Copy all the folders in the nand-extracteda folder over to your SD/USB.