Screw removal
I took a pin punch and drove the staked metal back away from the screw slot, placed an old screw driver in the slot and tapped down some times the tapping will loosen the threads, then took a hollow ground blade screwdriver bit that fit the slot and turned it out using the ratchet handle in a Chapman grudriver set. Heating might help. Some Izzy assembled shrouds have been soldered in place, afer removing the screw you might have to heat the shroud/trunion area to melt the solder.