Check whether the zipper pull is still attached to one side
If the pull came off completely, align both zipper tracks evenly
Insert the teeth from both sides into the zipper pull at the same time
Pull the zipper pull upward slowly to rejoin the teeth
If one side is loose, use pliers to gently tighten the zipper pull
If the zipper pull is bent, reshape it carefully with pliers
If the stop at the bottom is missing, replace it or sew a new stop in place
If the slider is damaged, replace the zipper slider
If the teeth are misaligned, straighten them before reattaching the pull
Test the zipper several times after repair
Replace the entire zipper if the damage is too severe