Honestly, the best way, money aside, is to drop that motor in a shipping crate and send it to a reputable engine builder to have it done. No offense to you at all, but what if you miss something else? You're already going to be into the motor for more than it would have cost for a builder to do it the first time. Let's face it, the money is an issue, or you wouldn't have asked for opinions on how to fix it without having to swap pistons. The thicker head gaskets will allow the compression to be lowered enough that there is no need for a $600 cam swap. You can use your existing cam.