compression test isn't the hardest thing in the world, providing the plugs are easily accessible... simply remove plug, turn the engine over with a compression tester in the hole it came from, repeat for all 4 cylinders.. you are checking for all similar readings, if one is significantly lower than the rest then it looks like head gasket issues. also, as stated above water in the oil is an easy spot, but not foolproof: just because the oil is ok doesn't mean that the head gasket is sound, and vice versa, just because your oil is emulsified not definitely a blown gasket