does engine have to come out of car to change head gasket? on 2008 Pontiac Solstice

i was in oreillys and 2 guys came in. one had a solstice with a blowed head gasket. the other was telling him the engine had to come out to change it. looking at pictures i don't see why the engine whould have to come out! who is wright?

Asked by for the 2008 Pontiac Solstice