Easy , as long as you can get the old one out , they become stuck due to grime and heat etc.
1) lift up you back seat , you should see two wires , one going towards each wheel .
2) unclip the cable to the failed sensor and push the grommit through to the outside of the car.
3) remove the wheel , jack car up properly , axle stands if you have them .
4) you should be able to trace the cable in its plastic holders down along the rear suspension arm to the rear of the brakes.
5) its just held on with an allen keyed bolt . and should move towards the centre of the car.
6) reverse procedure with the new part .