Youve got to chop them off with a cutting disc,leave a couple of cm on all the way round then tidy up with grinder when you can see the lip of the chassis,inner sill etc.
You can't just drill the spot welds because they're seamed as well. Cut them off, then grind the remains off and buy new ones. When you're doing the inner sills( which will need doing) weld in some captive nuts and bolt the new ones on.
