Instructions
Turn off your PlayStation 3 and PS3 controller when replacing the grips. If you don't, you could accidentally hit a controller button and perform an unintended command on screen. Turn the console off either by holding in the power button on the main unit or by holding down the "PlayStation" button on the controller and selecting the "Turn Off Console" option.
Pull the existing grips off of the arms on your PlayStation 3 controller. These grips are made of rubber and fit tightly around the arms. Pull them downward away from the controller to separate the grips from the main unit.
Push your new grips up onto each of the controller's arms. Feed the arm of the controller into the opening on the grip. Slide the grip up the arm of the controller until it won't go upward any farther. Repeat this process with the other grip on the other arm of the controller.