Rocker cover

OK, what's the secret to getting the rocker cover off a 225 with air.

Any tricks, tips, secret incantations etc.

Bettsy has been running very poorly of late. Fixed some choke problems, changed the cap and rotor, new wires coming (although, all plugs are firing evenly).

Now, has steady misfire, at least two cylinders.

Got the cover off (going to set valves), but, needed about six hands to do it. Putting it back on without destroying the new gasket, looks pretty un doable.

Will do compression test after I get the valves set. The standard .010/.020 In/Ex what everybody uses???

Any ideas greatly appreciated.....

Al(BWA)