John C Frederick , MD March 29, 2015 Appliance: Model KSB50B3 Replacment of blender drive coupler I followed a YouTube video which showed that you just use a screwdriver to pry up the old head and screw on the new one. Took about 15 minutes because I was trying to be careful to not strip the screws, but could be done more quickly. Do-It-Yourself Rating: Repair Time Estimate: 15-30 minutes