Looking for good guide for adding extra parts to body.

[shaidien]

Trying to add buthole to all my bodies but it keeps giving me error . A guide or walkthrough would be nice. 

Butthole_0.nif.obj

[shaidien]

Was trying to get the weight in outfitstudio but it won't save the new paint. In fact the bones won't stay in the bsdismemberskininstance. I just can't seem to figure out why it won't let me all the sudden.  Any ideas or pointers in right direction would be welcome. O and when I use nifscope to add bones outfitstudio gives error and closes .