Things You Will Need
Socket wrench and sockets are recommended but open end or box wrenches will work, replacement roller, C-clamps, 2x4 inch board cut to proper length, Silicone or Teflon based penetrating spray lubricant,
Garage doors should be opened prior to working on the hinge and roller assembly. This will help reduce the pressure on the spring and cable. Next install C-clamps under the bottom rollers on each side of the door on the garage door tracks. You can also use a long board wedged under the door to secure it in the up position. If you have a garage opener, unplug it to prevent anyone from accidentally activating it while you are working on the door.
When the hinge is loosened the door will have a tendency to sag. The door will need to be braced to prevent it from sagging and potentially breaking. This is where a helper can come in handy to hold the panels in place, or if working alone, a 2x4 cut to the proper length can be used as a brace to hold the door panels up. If a board is used, I recommend attaching two other pieces of 2x4x18 inches across each end forming a "I" shape. This will help hold the two door panels in place and act to stabilize the brace to help keep it from slipping while you are working.
The next step is to remove the bolts holding the hinge in place. Tip the hinge outward from the door to disengage the roller from the track. The roller will now slip out of the hinge. Sometimes a little force with a hammer may be necessary to free it. If the hinge shows wear it would be a good time to replace both the hinge and the roller. Take the old hinge and roller to the hardware store or home center to make sure you get an acceptable replacement. Most hardware stores carry an assortment of different sizes and manufacturers. You can also find the necessary parts on-line. If you have to order the parts, logic would dictate that you order the parts prior to beginning the removal/replacement process.
The installation of the new roller is the reverse of the removal process. Slip the end of the roller into the hinge in the correct hole, tip the roller into the track, and attach the hinge to the garage door panels with the bolts that you removed earlier. Lubricate the roller and hinge, remove the support braces and the C-clamps. If you have a garage door opener, disengage it. Next test the door manually a few times. The panels may not align properly and a minor adjustment to reposition the hinge slightly may be needed. Make sure the bolts are tight and reengage the door opener. Plug in the opener and test the door again to see if it operates properly.
Garage doors need to periodically have parts repaired or replaced. Follow the steps in this article and you will be able to safely remove the hinge and roller assembly and replace the roller.
Tips & Warnings
One of the most common problems with garage doors is a lack of lubrication. This can lead to breakdowns. Lubricate the moving parts every six to twelve months depending on the environmental conditions where you live. Also, while you are lubricating the door, inspect the door for any loose screws and tighten them as you go. In addition, look for any frayed or damaged cables, broken springs, misaligned track, or loose chain if the opener is chain driven. Basically, inspect all of the doors moving parts whenever you lubricate the door.
Always unplug an electric opener before servicing the door.
The springs, cables and bottom brackets are under extreme tension and can break without notice. You should never attempt to replace or adjust cables or springs. You should always call a professional if they break or you think they need adjustment.
Whenever working with tools or chemicals such as lubricants, safety glasses are recommended