Specifically, for the 2009 and earlier models of a car, the upper 
Control Arm ball joint cannot be replaced individually though if it is worn out then the best option is to replace the entire control arm. To change the lower balljoint, the front wheel has to be loosened by removing the lug nuts the front part of the vehicle lifted by jack and the weight should be secured on two jack stands before the wheel is detached. Next, take out the cotter pin and unscrew the balljoint to 
Steering Knuckle nut halfway or less. Direct the balljoint separator or puller onto the balljoint stud through the steering knuckle in a manner that observes that the nut stays half screwed on because it causes the balljoint stud to snap off violently. Lastly to detach the ball joint from the above mentioned point, first take off the nut and then take off the balljoint from the knuckle and also take off the fasteners from the attaching stud of the balljoint from the lower control arm. It is the reverse of the removal process, where all the suspension fasteners should be tightened to specific torque values; for the Lower control arm ball joint castle nut, use of new cotter pin should involved proper alignment of the hole on the ball stud with the slot in the nut without using a wrench to loosen it. For vehicles made starting with 2011, ball joints are rebuilt or replaced with balljoint press or hydraulic press equipped with special adapters; if adapters are not available, the control arm should be removed and the balljoint replaced at a qualified facility.