(1) Pried old selector knob off carefully by placing a putty knife on cooktop surface under knob (to protect glass cooktop) and slowly applied upward force on bottom of knob with a flat-bladed screw driver to gradually lift knob off post.
(2) Red model number on bottom of cooktop to ID correct cooktop parts on website. Used images on AppliancePartsPros.com website to verify I had the correct part - the images with the 1" grid on them are especially helpful to compare sizing with actual part.
(3) New knob slid onto post by hand & seated with firm downward pressure
Fast and Easy