The running boards (steps just inside the door) on my 63 are really badly rusted and so is the support that runs underneath, is there a way to just cut the spot welds on the running boards to pull them or does it require alot of cutting to get them out to weld in new ones?

 

Most spot welds can be drilled out! that is usually easier!

 

most autopart stores sell spot weld cutters fairly cheap or you can get them online also. get the right size for the diameter of your spot weld. i buy a couple at a time since i bust them a lot.
as far as getting All the running board and step plate out that isn't easy because the thing runs clear up under your pillars in front and is welded to the riser plate in back so it is hard to get to with a tool. depending on your situation you may have to just cut it at the front pillar support and graft on the new one. if need be post some pictures of what you've got, my experience level is minimal but the froum has several talented experienced people that can help

 

Finally got the paint stripped off the running boards, also the rocker panels underneath are rusted bad