Toyota Repair: AC belt on 97 Corolla, tension bolt, head bolt

Question
I have a 97 Corolla with 107000 miles on it.  This past weekend the AC belt broke.  I bought a new one, and then I removed the alternator and belt to try to get the AC belt on.  However, I cannot get the tension bolt (the one in the pulley) to loosen.  The head bolt has gotten stripped in trying.  My first question is: is this a bolt, or a nut? Was I turning it the wrong way, thinking it was a bolt going in (like the one for the alternator was), or is a bolt coming out with a nut on the outside of the pulley?  

My second question is: recommendations for trying to get this bolt loose? I've tried sockets, wrenches, vice grips and a pipe wrench.

Thanks.  

Answer
I think you are talking about the a/c idler pulley, there is a 14mm nut on the front of the pulley that you have to loosen then there is the adjuster bolt below the pulley, you need to turn it to the left to move it in so that the new belt can be put on.