Need modding help

[Slipofmind]

I could use a little help with my mod.. I am using 3ds max 2010 I have all the niftool plugins. I am working on a fallout NV mod. I am able to import my characters mesh, textures and skeleton with out any problems. I am new to modding fallout NV. what I am trying to do right now is get my character to so up nude in my game.... Yes i know there are hundreds of mods that will do this for me. but am trying to learn it for my self. now after deleting the underwear and then exporting everything back to Fallout NV and loading the game my character shows up blank ...all i see is the head and no body.. I have been searching for day for a tutorial for this but cant seem to find one. Does anyone have a link that could help me... or point me in the right direction?