Install the new ball joint from the under side of the lower control arm, use a rubber mallet to tap around the outer edge of the ball joint to keep it from falling, select the correct spacer that will allow the ball joint to pass through as it is pressed on to the control arm, see image.
Place the adapter shown in the image over the spacer.
Install the ball joint tool as shown in the image using the remaining adapter with the larger opening at the bottom, tighten the screw to press the ball joint on the lower control arm, make sure that the ball joint is fully seated but don't over tighten it to avoid damaging it.
Install the new snap ring provided with the new ball joint using snap ring pliers.
Install the new grease fitting, it should end up facing the front of the vehicle for easy access.
Install the new dust boot over the new ball joint.
Lift the lower control arm as high as it will go without lifting the vehicle and using a long pry-bar slide the steering knuckle over the new ball joint.
Install and tighten the ball joint nut properly, install a new cotter pin, bend the ends using needle nose pliers to keep it from falling off.
Apply grease to the new ball joint through the grease fitting using a grease gun.
Install the outer tie rod end back on the steering knuckle, tighten the nut properly and install a new cotter pin.
Once you are done replacing both sides install the wheels back on the vehicle, tighten the lug nuts to the specified torque listed on your user's manual and take it for a test drive.