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There should be a drive belt layout diagram on the support bar behind the radiator. If not we have a pic of a L67 SII 3800 engine at our Tips & Maintenance subforum you can use. See link below.
Click here
Just use a rachet preferably a breaker bar with the right sized socket (15mm) and turn counter-clockwise (direction toward the firewall) on the drive tensioner pulley to get the old main serpentine belt off. Same goes for the supercharger.
Keep in mind that the 1997 model was delivered with two different sized main serpentine drive belts depending on month manufactured so make sure you get the right size. Either 93.5" or 93.0".
Gatorback Gatorback Part # 4060935 93 1/2" BELT - Matches AC Delco 6K935
Gatorback Gatorback Part # 4060930 93" BELT - Matches AC Delco 6K930