I just did the clutch in my 2012 GT
this weekend. It's pretty straight forward. Just takes a lot of time unless you have a lift. I did mine by myself on stands and it took a total of about 12 hours. Here are a couple notes from my install.
Drop the H pipe and one of the catalytic converters (I only had to drop one to get the bell housing to clear). They are attached to the manifold by two 15mm nuts.
Pull the sub frame connector just bellow the bell housing (four 15mm nuts).
There are several sensors connected to the trans, make sure you get them all disconnected.
Disconnect the clutch line. I used a vacuum cap to plug the line so I didn't loose all of my fluid. be sure to disconnect it where it connects to the slave cylinder, leaving the 90deg elbow attached to the line. Use a small flat head screw driver to pull the retaining clip and be careful not to loose it.
Disconnect the shifter (from either the trans or the body of the car. I have an MGW race spec, so it was easier to leave the shifter on the trans).
Remove your drive shaft (12pt 12mm bolts on the trans, 10mm 6pt on the diff and two 13mm bolts holding the center to the body). Be sure to mark both ends of the drive shaft so you line it up correctly when it goes back in. This is important so you don't end with vibrations. Chalk works great.
Remove the top two 13mm bellhousing bolts from the top of the car. The only this that worked for me was a long wrench with an angle on he box end. I had to put a breaker bar on it, because there isn't enough room to get good leverage on the wrench. These ones are hard to get form the bottom.
Support the back of the trans and remove the four 18mm bolts for the rear trans support.
Lower the back of the trans with a jack (to pivot the engine) and remove the starter (three 10mm bolts. The top one is hard to get to and I had to use a swivel and several extensions to get to it from above the control arm). The power and trigger wires are held on with 10mm and 13mm nuts.
Support the trans with a trans jack and remove the remaining bell housing bolts, leaving the two lower bolts in, but loose. Try pulling the trans loose from the engine. This gave me the most trouble as one of the pins used to line the trans and engine up was rusted to the dust shield. I had to gently pry that one side away from the engine.
once you have the trans far enough back so the input shaft clears the clutch, slowly lower the trans. Change out the clutch and flywheel (or have yours resurfaced). Be sure to follow the directions that came with your clutch for proper install. I always replace my pressure plate and flywheel bolts with ARP bolts, but that is just me. I don't know if the stock bolts are re-usable or not.
Change or inspect your throwout bearing/slave cylinder. Be sure to measure for free play and preload, so your clutch operates properly and has room to wear. Ram Clutch has a good tutorial about this on their website. Different clutches might require different preloads so be sure to check. Ram also sells slave cylinder spacers. It's good to have some just in case you end up needing them.
Get the trans up and back in place. Make sure the angle of the trans is the same as the engine as you get the trans slid into place. Don't force it, just gently align the trans until you feel the input shaft slide into the clutch disc. Once I thought it was in the splines, I put my trans in gear and tried to twist the output shaft the be sure (if it spins your not in). Don't forget the put the dust shield on between the trans and engine. I was able to get the trans about a half inch from the engine block and slide the shield behind the flywheel.
Everything else from here is just re-installing the remaining wiring and parts you removed. Be sure to check that you haven't pinched anything in the trans tunnel after the trans is back up.
I hope this helps and keep in mind this is just from my experience doing the job. I am by no means a professional or mechanic. Just a DIYer, so do this at your own risk.
Ok, I guess that was more than just a couple notes.