Big C Jeep

I have a manual 1994 XJ 4.0L 4WD and one night I was turning left onto a road from a stop light. All of the sudden my clutch made a clunk sound and the pedal went to the floor. With the momentum I had left I pulled into a parking lot and called a shop to tow it. The shop said that the transmission had to be dropped and said it would cost $1,400, which is mostly labor. So i told them not to do anything and that I would come get it and work on it in my shop class and school. I have been doing some research on how to and was wondering if I could get any pointers.