@turkeylegs on your 360 S the GPU is part of the CPU. It is not impossible but will require to have the tools to do a total reball. That means you would at minimum need the stencils, a BGA reflow machine and a new processor. That is where you run into trouble. Those do no longer exist. That means you would need to use an old/used processor. Nobody can/will work with processors that nobody knows anything about. Think about it, you may be buying somebody else's problematic chip.