Step 24: Drill the Knobs
Most dimmer knobs are designed not to be interoperable. In other words, they all have annoying plastic notches in them which prevent them from being put on a generic potentiometer.
To fix this, drill out the mounting holes of the knobs using a 1/4" drill bit. Be careful not to drill all the way through the knob. The goal here is just to hollow out the mounting hole.