Before you begin, it's important to make sure your garage door operates smoothly. Undue strain can ruin or shorten the life of your new opener. Start by cleaning the tracks and rollers. Lubricate the roller bearings with silicone spray but avoid getting any on the tracks, as it will cause dirt buildup.
Test door balance by raising the door to midpoint and releasing it. It should stay put. Raise or lower the door another foot or so, and it should open or close slowly. If the door goes up or down past the midpoint, the torsion spring (the spring directly above the door opening) may need to be adjusted or replaced.
Never self-service a torsion spring system. These can be very dangerous and are best handled by a professional.
Don't adjust or replace extension springs (one above each track) without the instructions supplied in the owner's manual or without the proper replacement parts.
If you’re replacing an old garage door opener, disassemble it and set it aside. Remove any ropes, locks and other parts and hardware from the garage door.