FOLLOW THESE STEPS IF THERE IS NO SPEAKER PRESENT.

Use a flat head screwdriver to remove the rotating control knob from the encoder shaft

Remove the mounting threads on the outside of the encoder shaft with a 11 mm nut driver. Make sure to remove all nuts and lock washers from these mounting holes.

Place the front enclosure on a flat surface, and orient the front to be facing down. Maintaining this position, remove the encoder shaft out of the mounting hole.

Flip the front enclosure and place it flat in front of you. Slide the interface board up vertically to remove it.

When reassembling, orient the indent on the control knob to be 180 degrees from the flat part of the encoder shaft. Push the control knob into the encoder shaft.