Originally Posted by subzali
It's not uncommon for heads to be difficult to remove. There are little slots on the side you can put a large screwdriver or pry bar and pry up or whack with a mallet. Hopefully you'll be golden after a head rebuild if the engine turns over smoothly.
It's also recommended to chase the head bolt threads in the block before reassembly. I'm sure you're already getting good help with this project though
before I lifted the engine by the head with all the bolts out (wow) I whacked it to death and used the side slot to pry extensively, but I haven't given up yet.