De Dietrich DRL880ES Guide D'utilisation page 38

How to reverse the door
 Ensure the unit is unplugged and empty.
 To take the door off, it is necessary to tilt the unit backwards. You should rest the unit on
something solid so that it will not slip during the door reversing process.
 All parts removed must be saved to do the reinstallation of the door.
 Do not lay the unit flat as this may damage the coolant system.
 It is better that 2 people handle the unit during assembly.
Refer to the drawing below.