Switch off the lights.
Open the trunk.
Open the side trim panel.

Remove the tail lamp connector
Simultaneously press retaining lugs 1 in the direction of the arrow and slightly pull out the bulb holder with the bulbs.
Remove the connector for LED light functions from the top of the bulb holder.
Pull the bulb holder out with the bulbs.

1 Backup lamp
2 Brake lamp
3 Parking lamp/brake lamp

Press the respective bulb 1, 2 or 3 back and turn it counter-clockwise to remove it from the bulb holder.
Insert the new bulb into the bulb holder and turn it clockwise.
Reinsert the connector for LED light functions in the bulb holder.
Insert the bulb holder again and lock it in place.
Insert the tail lamp connector.
Close the side trim panel