Just wanted to let you all know that I completed this repair yesterday and no more screeching noise. I replaced the ac belt tensioner, deflector pulley, hydraulic tension pulley and both belts using this excellent DIY:
http://www.xoutpost.com/bmw-sav-foru...ent-3-0-a.html
Some notes:
1.) The DIY lists T50 to loosen the ac belt tensioner but I found out it's a T60. I did not have a T60 but was able to loosen it with a T55.
2.) For removing the ac belt tensioner there is only one bolt that needs to be removed after the belt is off. Not sure what the upper bolt in the DIY is for?
3.) All of the old pulleys spun freely unlike the new pulleys which had a little resistance to them. Before starting the repair I thought it would be opposite where the old pulleys would not be turning freely at all and jammed up causing the screeching sound.
4.) Putting the fan shroud back was a little tricky (took a couple of tries). There are clips on the radiator that the fan shroud slips into and getting them all in with one hand while holding the fan with the other hand was a bit of a circus (at least for me).
Overall this was an easy-medium DIY with the proper tools. I must have spent more time looking for and retrieving a socket, that I dropped while tightening the defector pulley, than the actual pulley and belt replacement.
Thanks for all your help.