How do I reset computer after changing the rear brakes and rotors, brake light is on and message stating "check brake lining". ? 2006 X5

Check the break fluid level.

The warning light may not have been reset, door lock actuator bad creating a short - blowing fuse, or bad switch.

check to see that the sensor wires that sense axle rotation are connected. Some are near the caliphers abd read the rotor rotation and in my car with rear drum brakes it is in the axle housing next to the axle bearing. Check that the sensor is compatable for the new application

One of your wheel sensors has triggered - needs brakes OR sensor has come undone. Sensors are on left front and right rear calipers. Brake light is on = low fluid. Get your brakes checked

Study light? Do you mean warning light?
There are sensors clipped into the brake pads on the front left and rear right wheels. When the brake pads get very thin, those sensors rub on the brake rotors, and the light illuminates in the dash indicating that it is time to replace the brake pads.
The light can also illuminate if something damages the wire to the sensor. I usually replace my pads before they get down to the sensors, so I re-use my old sensors. Although the wires are fairly well secured to the suspension, after a few years, the wires can get chaffed from the wind blowing them around, and the damaged wire can turn on the warning light.

Try re-bleeding ALL wheels starting with furthest away - pass rear, then driv rear, then pass front and driv front. That should get your pedal back. To reset light you need ABS reset tool and it's EXPENSIVE. Have a good competent shop reset it for you. Body shops can reset them also.

Make sure the mechanic checked the park brake shoes inside the rear rotors, they quite often break away from the lining and get wedged in the rotor, sometimes causing a constant squeal noise. I've also seen the brake pad anti-rattle metal clips become loose and wander in the caliper bracket, they lightly rub against the rotor and cause a squealing noise similar to worn brake pads. They are also very bad for the backing plates rusting out prematurely and rubbing on the inside of the rotor. Other than that he can just try to champher the edges of both front and rear pads to help dissipate the brake dust, from collecting and causing squeak noises.

this means you need brake pads and depending on where you bring it it will range from 80 dollars to 200 dollars for the front and the same around price if you need the rear. it will depend on what style brake pad and if you go for factory replacement it will be closer to the 200 dollar mark.

hope this helps. please ask any more question you have and good luck

its the brake pad wear indicator telling you your pads are in need of replacing