I need to "invert" a stamped steel part; at one end there is a spring
hook made with a 90 degree bend at its base. I need to flip this hook
180 so it is 90 degrees on the other side. The stamping is about 3/32"
thick and the hook projects maybe 1/4". I only have one chance at this.

I assume it is mild steel.

Cold? Hot? If hot how hot?