To remove
- Remove the MAIN INSTRUMENT UNIT (540) .
- Put the main instrument unit on a soft, clean surface on a well-cleaned worktop.
- Remove the glass: Remove the four screws from the underside, turn over the unit so that the back side is facing down, take hold of the sides and press in the catches with your fingers.IMPORTANT: Exercise great care. Do not touch the needles on the main instrument unit under any circumstances. This could cause faulty readings or damage the stepping motors.
- Lift away the glass.