Draining DEF E70

Remove the filler cap of the active reservoir (1) or the passive reservoir (2).

Fig 1: Identifying Filler Cap Of Active Reservoir And Passive Reservoir
Courtesy of BMW OF NORTH AMERICA, INC.
Service ports for the active (1) or the passive reservoirs (2) are located under the right side of the vehicle.

Fig 2: Identifying Service Ports For Active And Passive Reservoirs
Courtesy of BMW OF NORTH AMERICA, INC.
Remove the cap from the service port being drained and attach the extractor hose (1) to the port.
NOTE: Clean the caps for the service ports with water before reinstalling. Make sure the caps lock back onto the service ports.

Fig 3: Identifying Extractor Hose
Courtesy of BMW OF NORTH AMERICA, INC.
Connect the shop air to the vacuum block, and open the valve at the vacuum block on the canister for vacuum supply. Slowly open the valve of the suction line at the canister and draw off the DEF. Watch the level through the level tube. Make sure the exhaust hose off the vacuum block is situated so that it will drain into a suitable catch pan, in case the DEF extractor canister gets overfilled.