[Goldenfinger]

+1 for the angle grinder...

I used a 4 1/2" angle grinder as well to remove the entire lip from my drum and make all the cut-outs for my round basket from 1/4" steel plate... the only difference was that I changed out the standard cutting disc for a small diamond disc. They have the same size pilot hole to center the disc, so all you need to do is flip over the mandrel to secure it properly...