then let's make this simple, shall we?
download these two things:
the first one is the xinelib, the second is xine-ui (i know you said kde theme, but xine-ui is an internal project and is the one i've used so i can help you with it; it is full-featured too)
after downloading double-clicking them will open up file-roller so you can untar them; i usually untar things into my /home/username folder
you can always use the terminal to do your untarring of course
now in the terminal, cd into the xine-lib folder (the full name of the folder of course) and then do
su (enter root password)
now do cd into your xine-ui folder and do the same thing as before; to start xine, just type xine in a terminal