Remove the Cooling Shroud? 96 Ski

I'm new to snowmobiles, but I am a good shade tree mechanic. I have a 96 Ski Doo Formula SL with a 500 air cooled engine, seized. I have purchased a repair guide and wasted hours looking at posts all over the internet for assistance on how to get the cooling shroud off the top of the heads to even get started. My thin wall sockets are not even thin enough to fit over the bolts on the top holding it on the heads. Any help will be appreciated.

Remove the Cooling Shroud? 96 Ski