yep, on the drive.
I had the jack under the towbar, wheels on the ground, 24mm spanner 24mm socket I think is the biggest
Raise and support the vehicle.
Support the rear axle with a hydraulic jack.
Remove the ball joint nut from the top of the upper suspension arm
Separate ball joint from the arm with a ball joint splitter
NOTE: It may be necessary to strike the upper control arm with a hammer to separate the ball joint from the arm
Remove the ball joint mounting boltsfrom the differential housing.
Remove the ball joint from the differential housing.
INSTALLATION
Install the ball joint on the differential housing.
Install the ball joint mounting bolts and tighten to 136 N·m (100 ft. lbs.)
Raise the rear axle with a hydraulic jack to align the upper arm with the ball joint.
Pull the arm down on the ball joint stud and install a new nut. Tighten the nut to 142 N·m (105 ft. lbs.) you will need an 8mm spanner for this bit otherwise the taper will spin whilst you do the main nut up
Remove the supports and lower the vehicle