2004 sportsman 700 blew a hose and lost water, son drove it home hot, pulled in smoking oil at manifold and no water. Fixed hose, new thermostat, runs good except oil is going onto manifold and oil is full of coolant. Would you say this the head gasket or something worse? Does engine have to come out to replace head gasket? Procedure manual for head gasket replacement available? My mechanic abilities on a scale of 1-10 is an easy 8. What is the difficulty of this? Thanks.