Switch off the power supply and prevent it from being restored. Do not allow electric power to reach the unit any longer.
Release the fastener, and unplug the connector (k) from the onboard power socket.
If necessary, release the cable (g) from its fastening.
Undo the machine screws (c).
Take speed sensor (a) cautiously out of the axle box cover so as not to damage the sensing device.
Close the opening in the axle box cover.