2006 Scion TC Tensionor Replacement

Noises problem
2006 Scion tC 4 cyl Manual 50000 miles

Bearing sounds like its going on bad on either the tensioner or the water pump. I have a friend helping me that has quite a bit experience with car repair, so we tried replacing the tensioner, but the last bolt holding it in was too long to remove (it hits the frame of the car). Its very close to coming out, maybe a thread or two holding it on. In other forums (scionlife. Com) I had come across an article that mentioned having to rotate the engine to an extreme angle by loosening the s-pipe bolts and then the tranny bracket and the rear bracket. That seems like a rather worrisome thing to do, since I dont have a backup vehicle. The pipe looks a bit rusty and my friend is worried it could be risky, and might not come back together as easily as it came apart.

1st Question: Is it feasible to just cut the bolt and replace it with another minus a couple threads? Are these kinds of bolts common/replaceable. Does this sound like a good idea/bad idea.

2nd Question: If we cant cut the bolt and replace it, what is the best way to proceed? If we have to do it the way I read, would it be possible for you to guide us on where the brackets we would need to loosen would be located. There were no pictures in the post, and the repair manual we have is inadequate.