He can't access his system menu. Only has access to bootmii and priiloader.
Try downloading Dop-Mii_v12_CB2_BB2
Extract to freshly formated SD card and insert into your wii. Boot wii and Dop-Mii will start.
Choose to load IOS36
Install IOS60 v6174 apply all patches
Install IOS70 v6174 apply all patches
Install system menu 4.1
This should do it.
You will have to reinstall Priiloader after.
Edit: I just went back to the first post by junkmail and he gave you a guide by mauifrog that pretty much tells you to do this exact thing LOL. If you followed it you would be all sorted out by now.