How do you change the head gaskets 1972 vw bug and can I remove the shins to increase compression?

There are no gasketsused between the cylinder head and the cylinder, but there can be shims used to control compression ratio. The shims are used when the head has been flycut (machined) when it is being rebuilt. You can have the heads flycut to raise compression ratio if desired. Be careful with the air cooled engines because too high a compression ratio can be disasterous! A competent VW machine shop can give you more details