From
http://www.jibbingame.com/forum/viewtopic.php?f=2&t=2744
Adding grabs:
1. Find a grab pack that looks good to you in the forum (by searching grabpack im sure you can find multiple results)
2. Download by following the link and replace the other grab pack file (cross_in6.b3d)
3. Change clothing file names accordingly... such as Down Jacket.jpg for packs that don’t have many customizable options. or Front.png, Back.png, Arms.png for the LRG pack or anything like that...
Hints/Tips:
Put any unused grabpack files in the goodies folder and name them something that describes the pack
Keep the original pants and jacket files somewhere (the goodies folder is a good place to keep files when you aren’t using them) in case you lose them.
If that doesn't make sense, just reply to this post and I will try and explain.