Seat belts are an essential form of automotive safety equipment. They have saved many lives and prevented even more injuries since they were introduced. Having a sound and working seat belt makes every vehicle safer for its occupants. If you have a worn or damaged seat belt, it may not offer as much protection in the event of an accident and should be replaced. You can save yourself the cost of visiting a repair shop by installing the seat belt yourself.
Remove the plastic covers from all the seat-belt bolts. Pry the edges up with the screwdriver and the clips should pop off. In some cars the plastic may have a screw holding it in place. As you lift the edge, examine the point of resistance for a screw, and remove it if necessary.
Unbolt the seat-belt clip from the inside of the car. The bolt is sometimes quite long, so make sure you have enough space by sliding the seat forwards and backwards until you do. Unclip any wires attached to the clip as part of the seat-belt warning system, and use the painter's tape to hold them in place so that they don't slide out of reach under the seat.
Remove the belt itself. Remove the anchor bolt first. This is close to the floor on the outside wall of the passenger compartment. It is attached to the end of the seat belt. Unscrew the bolt and remove the belt. Again, the bolt is quite long, so make sure you move the seat around to give yourself space.
Remove the bolt holding the shoulder guide in place. This is usually located in the top third of the door pillar. It's very easy to find --- just follow the seat belt up from the last bolt you removed.
Remove the bolt holding the tensioner in place. The tensioner is either located at the bottom of the door pillar, close to where you removed the anchor bolt, or somewhere between the shoulder guide and the anchor bolt. Follow the seat belt from the shoulder guide and it will be easy to find.
Take the new tensioner and put it in the same place you removed the old one from. Bolt it down tightly with the same bolt that held the last one in place. You may also want to replace the bolt if it is worn or bent.
Pull the belt out gently and replace the shoulder guide by bolting it back into its hole in the top third of the door pillar. Make sure the bolt is nice and tight, but the shoulder guide can still rotate. This is essential for comfort.
Take the end of the belt and pull it down towards the floor. Bolt the end of the belt into the floor using the anchor bolt again. Make sure the bolt is tight.
Move to the far side of the seat. Remove the tape from the sensor wire and clip the sensor wire to the new seat-belt clip. Bolt the seat-belt clip in to place.
Test the belt by bucking and unbuckling it, pulling on it and jerking it so that it locks to make sure everything is working before you reinstall the plastic panels. Try everything to find a problem --- it is better to find it now than when you have an accident.
Replace the plastic panels covering the bolts. You may need to screw them in place.
