WARNING: This page is about a different car, the 2002 GMC Savana and 2002 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
Remove the oil pump bolt.
Fig 1: Oil Pump Bolt
Courtesy of GENERAL MOTORS CORP.
Remove the oil pump.
Fig 2: Oil Pump
Courtesy of GENERAL MOTORS CORP.
Inspect the oil pump locator pins for damage, and replace the pins if required.