has a pronounced squeaking noise

Hi,

Replacing brakes isn't too hard to do. First, here is a link that explains in general how it's done. You can use these as a guide:

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

Here are the directions specific to your vehicle. The attached pics correlate with the directions.

_________________________________________________________

2007 Mazda 3 L4-2.0L
Front
Vehicle Brakes and Traction Control Disc Brake System Brake Pad Service and Repair Removal and Replacement Front
FRONT
DISC PAD (FRONT) REPLACEMENT [LF, L3]
1. Remove in the order indicated in the table.
2. Install in the reverse order of removal.
3. After installation, pump the brake pedal a few times and verify that the brakes do not drag.


See pic 1


I hope this helps. Let me know if you have other questions.

Take care and God Bless,

Joe

Hello, I'm Danny.

To answer your question. yes, you always perform brake repairs and brake pad changes as a pair. It's not good to do repairs singularly to promote even wear. Here is a tutorial for you to view on how to change front brake pads and rotors:

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

I've attached picture steps below on how to change the front brake pads and rotors on your car. Hope this helps and thanks for using 2CarPros.