Q: Camshaft timing - 2000 Audi A6 V6

Hi - the only way to correct this is to do a timing belt & tensioner replacement - including the use of the Audi V6 timing tools to properly time the camshafts (relative to the crankshaft), and reset the camshaft phasers properly. Otherwise, you risk expensive damage to the valves from incorrect valve timing. There is no shortcut. I would recommend a timing belt replacement by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, and correct this problem.