To acquire access to the upper control arm, you have to first loosen the lug nuts of the wheel, lift the front part of the car, and place it on jackstands and then detach the wheel. Place the floor jack under the lower control arm near but not touching the ball joint and raise it just to the ride height level. Remove the sensor harness from the control arm and take care of the orientation of the harness; if there is a front brake hose connected, remove it. Take a few turns on the balljoint nut but do not remove it, then use a balljoint remover to unlock the upper control arm balljoint stud from the 
Steering Knuckle, then remove the nut. For 4WD models verify where the adjustment cams are in relation to the frame of the car. Lose the upper control arm pivot bolts and detach the control arm.. For installation, reverse the above mentioned procedure while it is important to adjust the mark on the adjustment cams and the frame for models with 4WD. Lose the control arm pivot bolts and balljoint nut and then tighten them to the needed torque and finally tighten the wheel lug nuts. Finally, check and have the front end alignment if the wheels are out of alignment you will need it to be realigned.