The problem with this is that by the time you heat around the screw, its such a small area to begin with and the screw is so small that the heat will almost instantly transfer. That is why I said to heat the screw til it was cherry red then give it a few seconds to cool (so you don’t strip the head) The screw itself will soften slightly which will allow you to get it out. If it were a bigger screw (ie lug bolt) then I would agree 100%… heat around it. But those screws are so tiny you would never be able to shock it quick enough to only heat around the screw… especially since I doubt the OP has Oxy/Acetylene torches and would probably just be using a simple propane torch.