The lesson here now is to not over tighten it when you reinstall it. There is no need to do anything other than make it just a little snug. The rotational direction means that even if just snugged it won't come loose.

 

Put a rag between the belt and the pulley.
Get a large crescent wrench.
Put that on the bolt

Now crescent wrench up at the 12 oclock mark.
Get a 5 pound mallet and whack it
right to left

meaning you are facing the truck.
You go from right to left
from driver's side to passenger's side.

Whack the top of the crescent wrench.
Don't hit the alternator pulley.

It will come loose.