Plug in and heat up your soldering iron.

Once your soldering iron is hot, prepare to desolder the ground wires (the wires connected to the cylindrical base of the potentiometer).

Grab the wire, and gently pull it away from the potentiometer.

Melt the solder on the ground connections by touching the tip of the soldering iron to it. Continue pulling on the wire with your other hand.

Once the solder is melted enough, the wire will easily pull away.

Be careful to not touch any other wires with the soldering iron.

Be careful when holding the wires, as they'll become hot really fast.

Use desoldering wick to clean up the remaining solder.