Separate the cover from the body.
Remove the drive shaft and the drive gear of the oil pump.
Wash the pump body with gasoline.
If the oil parts of the 1st pump are heavily contaminated, remove the oil receiver, take out the mesh filter of the oil receiver and clean it with it.
Check the gap between the gear teeth, which should be 0.05 mm (maximum permissible 0.20 mm), and the gap between the outer diameter of the gears and the bore of the oil pump housing, which should be no more than 0.15 mm.
Assemble the oil pump in the reverse order of disassembly.
[The text is based on materials from the website AUDImanual]