51 rear shock mount bolt

[Brad Hall]

How do you get the rear shock mount bolt out of a 51 chevy pickup. I purchased a new set of shocks and they require you to remove old bolt and weld the new one in but no instructions. My factory ones have never been swapped and they look to be pressed in not welded and and there is no bolt head on back. I have tried heat but no luck. Do they have to be cut and redrilled.