how do i skin the custom models in jka? and how do i add new heads, torsos, etc. for the custom models?

First, read this tutorial

http://web.archive.org/web/20030411053810/http://www.theforce.net/games/jo/skinning.shtml)

it's for Jedi Outcast, but Jedi Academy is almost the same except it doesn't use .surf files.

Extract the player folders as described in the tutorial. The six customizable species start with "jedi_"

jedi_hm = Human Male
jedi_hf = Human Female
jedi_kdm = Kel Dor Male
jedi_rm = Rodian Male
jedi_tf = Twi'lek Female
jedi_zf = Zabrak Female

Edit the files in those folders as described in the tutorial.

hmmm i already know how to skin but how do take the files from the jedi_hm and make them in to a separate skin by itself?

Like I already said, read the tutorial, it's described in there.

If you really "already knew how to skin" you wouldn't be asking such a basic question.

Read the tutorial.