After continued use, a zipper slider on your favorite coat or shirt may cease working. The slider may jam or partially break off or come off completely do to a faulty part. If this happens, it does not necessarily mean you have to replace the entire zipper or take the garment to a professional tailor. Putting on or replacing an old zipper slider is a project you can do yourself with a simple tool.
Remove the old slider if it is broken but still attached before you put on the new one.
Pull off the top stop on the side of the zipper that has the slider on it with a pair of pliers. Slide the slider up on the zipper until you reach the top of it and pull it off.
Thread the new slider onto the bottom of the zipper on the same side as the old one was. Guide the zipper track tapes through the slider and push it upward. Use a pin if necessary to guide the track tapes through the slider openings. Gently pull on the tapes to make sure the slider is sitting evenly on the track. Carefully pull up on the slider until the locked track teeth are visible at the bottom.
Pull the slider up and down on the zipper to make sure it operates correctly. If it is getting stuck, then you may need to remove the slider and reinstall it.