Spot weld cutter

Blair makes a good product, I finally bought a set last year and they work good.
I will also take a grinder to the top panel sometimes if it is not going to be re-used.
Also other times I will drill a small pilot with a 1/8 bit and follow with a 1/4 inch bit just thru the top layer of metal.
Nothing is real fast, just time consuming, but if you are careful you will not damage the metal you want to save.