shop says I need new brakes?

Here is a guide that will help with step by step instructions on how to replace front pads and rotors:

https://www.2carpros.com/articles/how-to-replace-front-brake-pads-and-rotors-fwd

Here is a video on an M3 which is going to be similar:

https://www.youtube.com/watch?v=3VWVmqKiScI

Below is the process from the manual that will give the additional details to accomplish this.

Please let us know if you have other questions. Thanks