[Xcrewchief]

This is what worked for me to loosen the fan nut : Use a 13 mm box wrench on the pulley bolt and lay the other end up on the tensioner pivot point. Then when you try to loosen the nut with whatever wrench you use (I used a big pair of channel locks), you loosen it while the tension on the wrench holds it in place.
For reinstall, I used an adjustable rubber filter wrench (an old one that I had in my 'Just-in-Case-I-Need-It' box to put tension on the pulley.

Great post and keep talkin', guys!