1999 malibu my break and abs lights are on in my dash my fluid is full but when i wiggle the sensor on the ?

side of the cyninder they go out i snaped of the piece on the sensor ans waited a minute and snaped it back in but the lights came back on the dash .how do i replace the sensor or stem the part connected to the cyninder does it pull off or twist off i dont want to break it its a 12 dollar part i should be able to change it out .. help..thanks |||should twist off.. but i would get a haynes repair manual to be sure because all cars are different... good luck!