camaro lead filler problem

[lukky 71]

im working on a 71 camaro rear window frame.in the top corners i have some small cracks and pin holes.the problem i have is the lead is in the way to do any welding and dont have the tools to remove the lead .what i have seen on tv and internet working with lead scares me. i have noticed people using metal type bondo.could you fix this area using this method or some other to do repair .i am cutting all other bad areas out welding in new patchs.any reply would be welcome thanx.