The fumes are obvious and respirator a no brainer, but frankly I'm more concerned about spatter using a torch. I just don't want to liberate tiny lead droplets or particles and have them flying all over her property. Even melting it with an OA torch causes harmful fumes. Use a quality respirator...

This will probably seem like an insane idea to many but please bear with me and provide feedback on whether it's realistic or not. Is it possible to create a big hot knife with a steel plate and an arc welder? A friend has a slab of salvaged lead in her yard that must weigh at least a thousand pound...