You are gonna need to tear the block down to get at the pistons. Pretty much you're gonna rebuild your engine. While you're in there, might as well upgrade everything (I hate having to take stuff apart multiple times when I could just do all of it at once). I'd suggest saving up for some forged rods and forged head bolts to go along with your forged pistons. And since you'll have it apart might as well replace the valves and vale springs with titanium ones (if you feel you're up for the challange). Basically, if you want to keep it simple dont get high compression pistons without solid rods to back up the power.