There are special sockets that have spiral cut edges designed for gripping rounded bolt heads in order to loosen them with a ratchet. You need to take one of the other cylinder bolt heads in to a NAPA, Carquest, Bumper2Bumper, or other major parts store to match up the correct special socket. Once you get the correct one, you simply hammer it on, insert an extension and use your ratchet to loosen it like any other bolt.
Here is a sample of one the sockets:
They are good for about 8 uses, then the spiral cuts are worn out. The above one is a brand I have used before - IRWIN and are widely availabe- even some hardware stores carry them
Is it safe to remove the other cylinder head bolts EXCEPT for the one with the stipped head? I thought the bolts had to be losened in the diagonal pattern to keep the head from warping.
You will be ok to remove one of the center bolts to take in- leave the rest as they are until you get the rounded one broken loose. If you havent yet, I would also pick up a can of PB Blaster(1000x better than wd40) and soak the heck out of the bolts and allow time for the PB Blaster to soak down into the head and the threads- this will help in breaking them loose
I'll contact you again if I need more help. You really got me moving forward again.
sounds good- have a great evening, and if you need anything else let me know...