Chaosmdk

Think I have a blown head gasket, truck sputters, and rough idle. I replaced plugs and cables, cleaned maf sensor, HAVE TO: replace o2 sensors ( bank 1 and 2 lean),and thermostat!? I have two questions! 1) how do I get thermostat housing off? I got out one bolt the other is seized bad, and stripped! I hammered slightly smaller socket on and used pull bar! ( nothin ) & 2) anything I can do short of pullin my untied engine apart and changing head gaskets! Just need a temporary fix till I can afford to get them replaced! Mechanic told me it would be $2300 and up to fix!!!! Ouch please help!