Create the following directory:
Now extract all the files you need from the mandalorians.pk3
Place the files (not the folders) into "C:\Windows\Desktop\New Folder\models\players\kyle"
Right Click on "C:\Windows\Desktop\New Folder" and select "Add To Zip" (which should be in the list if you have Winzip)
Select the following options in the WinZip window, which will appear:
include subdirectories: yes
include path: no
save as: "C:\Windows\Desktop\<whateveryouwant>.pk3"
Click "create" (or "ok"?)
You are ready! Place the pk3 into your "Jedi Knight 2/base" folder and start a new game/load a game!
An alternative would be placing the "models\players\whatever" folder AND files, you have extracted from the mandalorian.pk3 into the "Jedi Knight 2/base" folder. Thus you don't have to include them into a pk3.
I hope I could help you, young padawan.
Gidion, a.k.a. Dalboz