Putting a new clutch in is a pain in the a**. I put one in my 87 EGT. You have to remove both front axles and the transmission itself (and of course everything that is in the way of the axles and transmission.) If you have the right tools its do-able, but time consuming. It would be easier just to let a garage do it. As for a test to see if your clutch is bad, i really don´t know. Usually if it is bad you can just tell.