Is the crankshaft turning yet? If you're trying to move the valves by prying on the rocker arms, it might be necessary to thump the valve spring end of the rockers with a big rubber mallet after soaking the valve springs and stems down with a good penetrant like PB Blaster, WD-40, or Kroil. If the crankshaft is turning and the rocker arms aren't moving, it's time for a pretty detailed disassembly.

Edit: If nothing else is available, Diesel fuel makes a pretty good penetrating oil.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!