CPS?
 

where is located 2000 cherokee I6

At the top of the bell housing. Driver side, IIRC.

any chance of picture i dont know where bell housing is

The bellhousing is the part of your transmission that bolts to the back of the engine.
http://i14.photobucket.com/albums/a3...atlast/CPS.jpg

is it hard to replace and about how does one cost

http://www.jeepforum.com/forum/f13/e...riteup-557482/

And no offense, but have you met my friend Google? He gave me that link, plus told me that a new CPS runs around $72 these days.:)