I used a spot weld cutter getting them out, then realized an air hammer is alot faster and funner. As far as getting the new pans spot welded to the crossmember, I got everything in and fitted nice and tight, then just drilled through the new pans till I hit the crossmember, and pooled up a few spot welds. Leaving a slight amount of pan left, before drilling into the crossmember worked best I found out, that way when you spot weld, the heat will just burn through the small amount of pan that didnt get drilled. I did it like that so as to not drill any more than I had to into the cross. smoe of the areas by the firewall and corners where the kick panel area are just got spot welded, as it was hard to get the gun tip in there and still make good welds, so those areas just got an ample amount of seam sealer.