The wiper blades on a GMC vehicle should be checked every six months to make sure they are functioning properly. Wiper blades typically fail where the rubber compound meets the glass. When the rubber starts to peel, crack or disintegrate, you need to replace the blades with new ones. You can buy new blades at any auto parts store. To get the correct size, take your old blades into the store as a reference.
Pull the wiper blade away from the windshield until the wiper arm hinge locks into a vertical or perpendicular (to the windshield) position.
Swivel the blade assembly so that it is perpendicular to the wiper blade arm.
Undo the latch mechanism at the wiper blade to wiper arm joint. GMC vehicles use a self-locking joint on their wiper blades. Push down on the release tab on the top of the joint, and pull the blade assembly off the wiper arm. Note the orientation of the wiper blade.
Slide the new wiper blade onto the wiper arm until it locks onto the arm, keeping the orientation of the new blade the same as the old one.
Swivel the blade so that it is in line with the wiper arm, and lower the wiper arm down to the windshield.
