[T2] ignition switch removal, electric

[accessys at smart.net]

78 bus.
ignition switch has shorted and melted itself into solid block.

have gotten most of the way to it but Bentley is not showing it the way 
mine is.  how do I get the final couple screws to the ){(@#&# thing.

was lucky it failed behind house. $8 part, 80hr repair it seems.
any help would be appreciated.  can seen what the Bentley shows as the 
screws  but there is welded cover over them, (factory) and no apparent 
way to get those screws out..

am completely disassembled up to this point.  although cannot get ignition 
wires plug off switch and don't want to pull too hard.

thanks
Bob