I changed the piston rings on my SJ, I was dreading it, but apart from taking the head off, it's a case of removing the 'bracket' on the crank (I can't remember the proper name for these
), and pushing the piston out through the top.
You just change the rings, re-hone the cylinder with a £20 tool in a drill, and put it all back together again. I replaced the bearing shells also, but I wasn't meticulous, it took a couple of hours and 1000 miles later it's fine with no more smoke.

You just change the rings, re-hone the cylinder with a £20 tool in a drill, and put it all back together again. I replaced the bearing shells also, but I wasn't meticulous, it took a couple of hours and 1000 miles later it's fine with no more smoke.