how do I replace a rear main seal?
 

Ok the suckers busted. It leaks only when running.

I know I have to remove the trans, but do I have to jack the motor up and drop the pan too. Hard hard is it(I was thinking it can't be that hard, just get in there yank out the old one and slap in a new one).

I there anyway I could screw this up and break something?

you have pretty much said it. all you have to do really is drop the trans and of course remove everything in the way (clutch etc...)

then just carefully pry the old one out without gouging the crank. and put the new one on. i didnt have to jack the motor or pull the pan on mine.

hope it helps, take care.
adam

Its just a matter of gently ripping out the old one, and _evenly_ tapping in the new one. It was suggested to me, to add a little RTV on the OUTTER edge. Also use threadlock on the flywheel bolts as those can leak (let alone loosen).
http://www.dariusrudis.com/mustang/t...s/rearmain.jpg