I need to replace the right hand side reverse bulb on a 2002 A4 Saloon. Can anyone please help?

 

The rear reverse light, you meen the one on the rear of the car. j/k as for the bulb type, you can probably find that at a local auto parts store and as for getting in there to replace it the process is gonna be the same as a brake light. there have been a few post on that in the last few so do a search for brake lights and there are some good tutorials. And welcome to the forums.

 

on the b6 a4: open trunk, on the side, covered in carpet, there is a circle about 2 or 3 inches in diameter, pop the carpeted circle with a screw driver, there will be a bolt sticking out - unscrew it, once unscrewed pop out the light starting with the end near the trunk, be very careful not to drop it. once the entire taillight assembly is out unclip the back of it from the lense and that will reveal the bulbs. it takes a few minutes and be very very very careful not to scratch the paint and not to brake the pins - also do not forget to put the bolt back into place!