To change the tire lug: first take of the tire, Then remove the drum. This can be the fun part if you havent' done this before. They can be stuck on pretty good. Next take a hammer and try tapping out the broken lug. If this doesn't work take a big hammer and beat the thing to hell. It will eventually fall out. Take the new one and place it in and try and tap it in as far as you can then take the lug and screw it on. This will tighten the lug. make sure you don't strip the threads by over tightening the lug nut.