The problem is the plug is plastic and everyone tightens them way to tight.
After you get the old plug removed and the threads cleaned up. The job is fairly easy. On the new plastic plug, available from almost any hardware store, wrap several layers of the plumbers plastic tape around the treads. There is no reason for the plug to be more than finger tight. I have been tightening mine finger tight and doesn't leak and they come out easy. You can't cinch them up with a wrench because it is only plastic. When I say finger tight, I tighten mine as tight as I can with my fingers.
When I bought my previous TT the dealer put the plug in so tight it looked like he put a torque wrench on it and it still leaked. The dealer never used any plumbers tape on the plug.
BTW: There a couple different types of plastic they make those plugs out of. Most hardware stores have both types of plastic ones sometimes in different areas. Some are better types of plastic.