Warning: this is only for labs and may be illegal in some countries. I do not recommend you to do this and I'm not affiliated with any damages.
Please note that these are specialized lab equipment and very expensive (around 1 million dollars. maybe less on ebay). I recommend you buy used machines.
locate the fuses on the die using the microscope. you would see a little fuse bank (this is very hard to do)
Mill away the metal layer, Apply ion beam to blow or cut a fuse (Warning: this would need a exact schematic, hard to get also one mistake could destroy nearby circuits) also I'm not sure which efuse is for the bootloader.
Reassemble the device and boot it up. if it booted up then it's a good sign.