Chickering Type pinblock

[Bigeartb@AOL.COM]

List:
Removing Chickering type pin block.....screwed into plate from bottom of 
pinblock....two screws will not move and one broken off even with the plate. 
What is best method of removing each...the broken one and the two with heads 
still on them but rusted in the plate. Will heat on the plate damage the 
plate? Have removed approx. 15 bolts...only three left.

Tommy Black
Stuck in Decatur, Ala.