Raise door completely and disconnect power and the lifting arm of garage door opener.
Retain door by fastening “C” clamps under bottom rollers on each side.
With tension completely off of cable, thread the cable through the pulley. Remove using wrench and replace with new pulley.
Rethread cable through the pulley and retie loose end of cable from track support or attaching plate.
Slowly lower the door by hand to check that the cable is properly fed through the pulley