How to remove Ross knobs
The recessed knobs found on Ross effect pedals work well for protecting against the stray foot that could ruin precise settings or snap a pot shaft. However, removing them to access the pot nuts, which serve as the mounting points for the circuit board, can be quite difficult. Years of dust and grime can nearly glue them on, plus the shape of the knob doesn't allow for a good grip. The brute force of pliers could be used, but they could mar the knob. We need a specialized tool for this job.
First, you'll need a large paper clip. Straighten it, then bend it to the shape shown in the above photo. Squeeze your newly-made extraction tool together and insert it at the top side of the knob (see below photo).
Then, spread apart the jaws of the clip and postion them so the "teeth" hook under the knob's midpoint. Then, hook your finger in the top of the clip and pull (see below photo).
This tool has worked well for me, even with the most stubborn knobs. Try it out, and let me know how it works for you!