I never pry between the fins, they break easily!
All that should be required is to remove the bolts and kick the engine over but like suggested peviously but if someone has really "glued" the head down due to "leak frustration" you could possibly try this but it should not be necessary (FIRST make sure ALL TEN bolts & nuts have been removed, count them!)
Take a length of hardware chain and use one of the headsteady bolts to bolt the 1st link to headsteady bolt hole, loop the chain over the frame top tube allowing some slack in the chain and attach the chain to the other headsteady bolt hole.
Take a short piece of wood, broom handle or "sapling" and slip it between the chain and the top of the upper tube and carefully "pop" the wood upwards like a lever. If it doesnt come up check that all of the bolts have been removed, heat the joint interface and try again. If it looks like the head is cocking slip the lever from the other side and repeat