When replacing my cooling system I snapped the bolt head off the top thermostat housing bolt, making it impossible to remove the housing. So I will just outline what I did to remove it without damaging the bolt hole on the block.

1. I removed everything in my way to gain access to the housing (belt,a pulley, the radiator and brace as well as the front trim by removing headlight bezels and indicator plastics. There are 4 retaining bolts on coners of the front trim panel. All this may not be necessary...

2. Basicaclly I found myself cutting the housing using a angle grinder and dremel tool to extract the thermostat itself first. This allows the housing to be spun off the block counter clock wise unscrewing the bolt with the housing.

So although you sacafice the $30 t-stat housing, ur not risking damage to the bolt hole on the block. Although I did this process in a roundabout way bashing and yanking on it; the above steps would have made the painful process wayyyy easier. Also avoids blow torching in the engine bay which makes me nervous.