Windshield wiper motor

You should start by disconnecting the battery. The wiper motor is under the cowl

Wiper motor is in Park position
Negative battery cable.
Wiper arm assemblies.
Cowl vent grille.
Transmission drive link from the wiper motor crank arm.
Loosen nuts holding the drive link to the wiper motor crank arm and remove the drive link.
Electrical connector from the wiper motor assembly.
Radio.
Left defroster outlet from flex hose.
Screw securing the left hand heater duct to the engine cover shroud.
Heater duct by twisting it down and then out.
Three bolts securing the wiper motor assembly to the cowl.
Wiper motor assembly.

Install

Wiper motor assembly.
Three bolts securing the wiper motor assembly to the cowl.
Tighten
Bolts to 7 N.M (62 lbs. In.)
Heater duct by twisting it down and then out.
Screw securing the left hand heater duct to the engine cover shroud.
Left defroster outlet from flex hose.
Electrical connector from the wiper motor assembly.
Transmission to the wiper motor crank arm.
Lubricate the inside of the socket with white-lithium grease (GM P/N 9985885) or equivalent.
Reach into access hole and squeeze drive link onto crank arm using pliers.
Radio.
Important: Wiper transmission assembly must be assembled to the crank arm past the second detent so that the seal is compressed to a maximum height of 25 mm (1 inch).

Cowl vent grille.
Wiper arm assemblies.

Images (below)