snake07

I'm planning to replace brake pads and rotors for my S5 B9, never worked on the brake job for Audi before, I had some experience doing brake for Toyota, so how bad it is to replace brake pads and rotors ? do you need any special equipment ?

HCGxKaLiBeR

There are video guides online.
Front: Back:
Here are some basic tools you need:
If you don't have them, get it. These will cover all the bolts, nuts and most of your future projects.

Flexible Extendable Ratchet Wrench (This is important. There are some bolts and nuts behind the rotor are hard to get to)
Torque wrench
Extension and socket adapter set
Low profile M4 - M18 socket set
Universal Spline Socket set
Brake caliper press tool
Basic fluid extractor tool (For the overflow brake fluid after the brake piston are pressed back in)

Here are special tools you need:
Audi 8D0012244A Wheel Bolt Cap Removal Tool (Needed to remove the lug nut covers)
ODBII scanner tool that is able to do EPB reset (Needed to completely release the rear parking brake motor)

Consumable items:
Brake part lubricant
Brake cleaner fluid
Anti seize paste

From my personal experience... The video makes it easier than it looks.

The caliper bolts were really hard to break loose. They were really tight.
Mine was on jack stands. Not a lot of room to get leverage. Thanks for my flexible wrench, eventually I was able to get them loose. Man my hands were hurting.

The rotors were all rusted stuck on the hub.
Applied penetrating fluid. Been hammering and kicking them for a long time to get them loose.