The ear pad is held to the ear piece by 4 plastic clips. Gently pull the ear pad away from the ear piece to remove.

Remove the speaker driver by removing the screws above and below.

Remove the white plastic clip with a plastic prying tool. It's likely that it is stuck down with some low tack adhesive.

By pushing the blue clips towards the centre with a prying tool or something similar, the microphone boom arm is then released from the body of the ear piece.

To remove the boom arm, it must be de-soldered from the PCB