Don't know if you've taken care of the alternator swap but I thought I'd chime in anyway since I just did this swap on my sons 2006 CXS.
I purchased a brand new oem from Ebay. ACDelco 84009378 New Alternator | eBay
I took care of the leaky oil pressure switch while I was there.
I removed splash guard, bumper cover, headlights, engine cover, cooling fans, and serpentine belt. I didn't drain the engine coolant. The ac system was already empty because of the bad evaporator. I just lifted the radiator/condenser assembly up and away from the engine to make room to safely remove the alternator. Had to disconnect the ac line that was blocking the alternator.