I just did this. They make special broke-neck distributor wrenches, but I couldn't get mine to get on the bolt. So I found out I was able to put a regular wrench behind the engine between the distributor and the firewall and twist it in small increments until it was loose enough to spin.
Counterclockwise is advancing too, which I found to be counter-intuitive lol.
And it only takes a little turning to move it alot of degrees.
Good luck!
P.S> Make sure it aint hot or you'll have a heck of a time putting your feet on the exhaust and your butt on the radiator to get at it!