If I am correct they are riveted in? If so, the easiest way I believe is to get an acetylene cutting torch, cut the rivet heads off, or you could get a gas welding rig to heat the rivet heads to red hot and use a cold chisel to cut the heads off. Or, if you have a grinding tool, use a(some) cut off disc wheel. When I was in Germany and not a lot of specialized tools for cutting and such, a DREMEL tool, lots of patience and keep at it will get the job done. If you use a dremel, get the real good cut off discs. They are fibreglas reinforced and will last longer. If you just want to kill the whole day, use a cold chisel, 2lb ballpeen hammer, and a truck load of sweat to do it.
Seriously, I wish you the best, if you are going to do it by yourself. Glad the new ones will have nuts and bolts to put them it. happy stangin' jb1rd
