Dear sir i have an audi a8l v6 and i have changed oil my self but i still got the indecator comes on every now and then , is there a way to reset it with out going to the dealer. thank you

You may find one at a reasonable cost using google. Type into your serach box;
'Service manual for 2005 Audi A8L'

Unfortunately, you cannot. Before replacement you needed to check gauge by grounding wire to block to see if gauge pegs, if the gauge does not move problem is in the gauge. I have worked on so many different vehicles, so my thought might be on a non digital type gauge not a digital. If digital gauge disregard this test.

Audi doesn't provide free owner manual downloads.

It is not possible to have that reset or turned off "Service Due!" without using a diagnostic scantool connected to the data link connector of the car. This is the only one way to reset service due light on 2004 Audi A8.

The speed it controlled by the ECU and it cannot be removed. You may find someone who can reprogram the ECU. Know that you will void the warranty if you do this.

10000 km unless driving in dusty conditions then 5000 km

the diode maybe leaking or shorted out. It should only conduct one way.

your oil filter is under the front end you have to move engine splash shield.under the front bumper.

the oil filter is on the back passanger side just below the turbo the pipes from the oil cooler run into the filter housing

It's not that big of a deal. The air box comes out by removing two screws and a couple of hoses. Once it is out the top of the canister is easily accessible.