Spray the can of compressed air inside and around the joysticks to remove any debris.

There may be some debris that doesn't come off after blowing with the compressed air. In this case, you can use a paper towel or cotton swab to lessen the build-up and follow up with the compressed air.

Be sure to follow the instructions when using the compressed air can. Shaking the can may result in liquid being expelled instead of air. This may damage the controller.