Quoted from desertstorm (Karl)
"Proceed as follows to fill fuel system with fuel:
Connect a Vehicle diagnostic tester.
Switch on ignition.
Select Engine electronics in vehicle self-diagnosis.
Then select Basic settings
Select Checking fuel system pressurisation pump from the list.
Press Start button.
The fuel pumps start running.
The fuel pumps must run for approx. 1 minute to ensure that the fuel system is filled sufficiently with fuel.
Note
To repeat basic setting, switch ignition off and on once. Then start basic setting again.
Start engine after filling fuel system.
Run engine at moderate speed for several minutes and then switch off.
Check fuel system for leaks.
Erase entry in event memory using diagnostic tester.
After completing the repair, road-test the vehicle. Accelerate with full throttle at least once. Then check the high-pressure section of the fuel system again for leaks.
Note
If there is any air left in the fuel system, the engine may switch to the backup mode ('emergency running' mode) during the road test. Switch off the engine and erase the event memory. Then continue the road test.
You can do this with VCDS"
Thanks mate!