The last time it was a bolt on a Bomar hatch. The bolt that connects the support to hold it open in a position. I was trying to take it out and the head twisted off.

I took a very small drill and put a hole through the center (very important,,,, center exactly). Then kept changing bits drilling larger holes until it was about the size of the stuck bolt which was by now only a shell clogging the threads. Then I put in a tap and made new threads and put a new bolt in. Sometimes you have to go one size larger.

I would think with screws it would be easy,,, just put it in the center of the cross hatch and drill it out. Trying to save all the screws takes so much time it's not worth it. If you can heat it with Mapgas it works wonders but if there is any wood around it you boat will be on fire.