I think I need new brake pads

Good afternoon,

The light will come on when the fluid in the master cylinder gets low. That is an indication of low pads on either the front or rear of the car. Here is a guide to help you step by step with instructions in the diagrams below to show you how on your car.

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

Removing and installing or replacing brake pads on both rear disc brakes (Teves floating caliper)
REP-REP-RAE7034-3421200

Retaining pins and expanding spring: for vehicles older than 48 months it is recommended to replace the retaining spring!

So as not to damage the surface coating, if possible do not mechanically clean the guide surfaces for the brake pads on the brake caliper mounting bracket, but rather clean with brake cleaner BMW TI. number 83 19 2 154 780 and apply a thin coating of break pad paste BMW TI. number 83 19 2 158 851 (3 gr.) or 83 19 2 158 852 (100 gr.).

Spread brake pad paste onto the marked surfaces using a brush!

Observe regulation on applying brake pad paste to brake pads and brake anchor plates!

Remove wheels.
Remove brake pad wear sensor.
Lift out retaining spring (1).
Remove cover plug (1).
Unscrew guide bolts (1).
Withdraw brake calliper backwards.

Attention!
Tie brake calliper back and do not allow to hang from brake hose.

Installation note:
Tightening torque:.

30-5 Nm Clean guide screws only; do not grease.

Check threads. Replace all guide screws which are not in perfect condition.
When pressing down piston, note brake fluid level in expansion tank.
Overflowing brake fluid will damage the paintwork.
Turn piston back fully with special tool 34 1 050. In the event of one-sided brake pad wear, do not change brake pads round.

Remove outer brake pad.
inner brake pad is located with its spring in the piston.
Clean brake pads.
Do not grease backs of brake pads sleeve.
Check minimum brake disc thickness:

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.