modify cj's skin?

hi, I have been trying to modify CJ's skin but havent been having any luck.
I want to add a tail to the legs.dff model, and theres the 3 clumps, one for fat, one for ripped and one for normal.
i tried to add the tail in the following fashion:
-skin modifier on the original mesh
-add the bones to the skin modifier
-click the 'skin the character' button in the KAM script.
-import and move the tail.
-go to original mesh>editable mesh>add list>tail.

i imported the 3 clumps, hiding the previous and doing the same procedure as above.
then i unhid the 3 (ripped, normal, fat) but it only allows me to export one clump, so the game crashes when i replace the original legs.dff with my modified one and i choose to remove legwear.

any help is appreciated, thanks.