Dumb brake maintenance questions

[Rocket Science Racing]

Hi all,

I'm heading into some brake work on my A4. A few dumb questions:

1. How do you get the caliper off when there is that ridge of rusty rotor
material around the edge?
2. Do I really need the special tool to get the rear pistons back in? If so,
do I need the Audi tool, or will another do?
3. Any other tips, hints, techniques I should employ?

Thanks!

Scott
98.5A41.8Tqm