To remove the audio or COMAND unit on the A and B class, you need to gain access to the four torx screws that hold it in place.

The procedure is as follows: -

• Remove air vent
• Remove panel that surrounds the airconditioning controls and lower control panel if present.
• Remove 4 screws that hold the head unit in place.

Remove air-vent.

This is done using the Mercedes pulling hooks. Close the air-vent (which prevents damage to the mechanism) insert the pulling hooks into the catches which are visible through one of the top slots on each side prising them inwards whilst pulling the vent out.

Disconect the connector to the hazard warning switch / airbag-off lamp and then remove the vent completely.

Here is a picture of the side of the vent after removing it, you can see the catches - the protruding part holds the unit to the dash board, and is levered inward with the pulling hooks.

Remove lower panel

The lower panel is removed by levering it outwards from the bottom, near the edges using the Mercedes plastic wedge tool (or something else hard that will not damage the panel).

I used the pulling hooks after prising the panel forward with the wedge.

Once the bottom edge is freed (and quite a lot of force is needed), then the top releases at the sides by pulling sharply.

Do not put any pressure against the metal trim at the sides of the central console, they bend or dent easily. Also ensure that pulling hooks are fully inserted as the panel is two pieces and you may split it in two.

Once it is all removed, it will look like this, and you can see the 4 torx screws that hold the audio unit in place.

Remove the four screws and the audio unit can be slid out.

Note how the wire to the hazard switch is routed, it is clipped into place on the left hand side of the vent hole, and passes through the hole visible in the centre of the picture.