Hi Munir,
look here for some (fuzzy) pictures:
http://www.audiv8.com/german/faq/faq_show.php?id=150I try to translate the instructions picture-wise. All advises (RH and LH) in driving direction!
1st. pic:
Drain the coolant at the lower side of the radiator meanwhile the coolant reservoir cap is opened.
Withdraw the upper coolant hose on the RH cylinder-block between the timing belt covers, as shown in the picture.
Then withdraw the lower hose. The thermostat is fitted behind it´s cap.
2nd pic:
Screw out the two cap bolts. Therefor a TX 30 Torx wrench is required. Manipulate the old thermostat out of it´s housing.
Clean all seal faces.
3rd pic:
Fit in the new thermostat. The small vent valve (as shown in pic 3) must be bound upward.
Reinstall the thermostat-cap by using a new seal. Tighten the bolts with 10Nm.
Forget about pic 4 and reinstall the two coolant hoses.
Filling and bleeding (not shown in any picture):
Switch ignition on. Engage the AC to HI-level. Turn ignition off.
Fill up the coolant (total 8,5 liters) 50 :50 with G11 or another coolant in the same color (green, blue or red) your system was filled with.
During filling procedure, compress the upper coolant hose a multiple times to support deaeration of the cooling system.
Close the cap of the coolant reservoir as it is full.
Start the engine (AC still HI) and keep it idling with increased revolution level (2000-3000 rpm). You may exceed 4000-5000 rpm for short moments, even to support bleeding.
After engine has reached about 100°C stop engine, wait for 5 to 10 minutes and open coolant reservoir cap CAREFULLY (pressure).
Top up coolant to max and close cap. Start engine for another while and add coolant if necessary.
That´s it.
