Wiper arms are durable and they will likely not need to be replaced that often while you own your Audi. However, if an owner does need to remove them, the task is fairly simple and requires only a socket wrench.
If you will need to use the same wiper blades, they will have to be removed from the arms before the arms are removed. Removing them is simple: lift the blade off the windshield, undo the the release mechanism and pull the blade off the wiper arm.
Wiper blades and arms are part of a wider system. Ultimately, it's the motor that that moves the wiper arm back and forth. The arm itself easily detaches from the rest of the system. At the base of the wiper arm, there is a covering. Remove this and there will be a nut beneath. Remove the nut with a socket wrench and the arm will come off with a little rocking back and forth.
A wiper arm can be removed without accidentally damaging the windshield. The wiper blade itself can be left and separated once the arm is removed. If the blade has been removed, a towel can be placed under the arm's bare hook to keep it from rubbing against the windshield.
