Hey there
First you have to know, that the charakter clothing (yes, also the armors) are the hardest object in LiF to mod.
All of the female and all of the male ones are clumped together in one file for each. Those are named female.dts and male.dts.
Imao the editing or just viewing of ALL those contained meshes are the hardest/impossible parts of LiF-modding.
I don't know anyone who has managed to modifier those meshes.
(Thes informations are very trivial. Maybe someone else have more or other ones about current modding progress.)
Much easier is to edit or complete replace the textures of existing charakter clothing (also armors).
Conclusion of this part of my post is: You can add and modify 3d models like buildings or weapons. The charakter clothing is sadly a deadzone.
To edit those containing .dts you need some expensive professional 3d-studio-software or use the torque3d engine in combination with the (very important) 1.2 toolbox of that engine.
This is all i know and i can pass to you. Hopefully there will be some 3d-modelling veteran who can tell more about this.
P.S.: I'm very sorry for my skills to write in english. Maybe this writing didn't too much pain to your brain