There are a bunch of how to books on engines. The two stroke glow engine is almost a no brainer and nothing in there to do a lot of hard thinking about. One of my LHS has several books on them. You can find how to books in the tower catalog and sometimes in mags like MAN. To hold a piston in place you can buy one of those cool little piston holders that thread into the plug hole or make your own from an old glow plug and piece of brass rod. A very simple way is to slip in some nylon thread into the glow plug hole and fill the combustion area up then just rotate the crank. Getting an instruction book on engine repair is the best idea though so you aren't going in blind. Going into that engine is a good way to learn something but I always ask myself if an engine is worth the time and money to fix?? If it is to you then by all means go for it.