I used one of the big 21 piece "G-Clamp" style swivel / ball joint removal kits (like E-Bay 401674598831) to do my right hand side steering joints back in the early summer last year. Allegedly the 10 piece ones don't have all the sleeves you need. Did the deed but really struggled with the top joint. Wound it up uber tight with a 4 ft scaffold pole 3/4" drive breaker bar and basically left it for three days giving it the occasional heave and obligatory whack with a club hammer when I felt like it. It gave in on the morning of the third day and actually came out quite easily. Bottom one wasn't quite as much of a struggle but still took some serious heaving. Didn't like the way the screw rubbed against the top joint bore when wound up tight so I made a top hat shaped bush protector from alloy to keep it straight. Despite being seriously hefty that clamp body bends! The E-Bay pictures don't give a proper idea of how massive, and heavy, it is. Dunno if the straighter pull helped things move or not. Would expect it to.
That being quite enough excitement for a while I left the left hand ones until October. In the interim I made a knock off of the pukka Sykes-Pickavant 1877100 tool (https://www.chrometrader.co.uk/automotive-tools/steering-suspension/ball-joint-removal/sykes-pickavant-18771100-swivel-ball-joint-tool-d2-p38-c-w-press-frame-ram.html) using the 12 ton ram and slotted bar out of my big hydraulic puller set. Just had to make a base to support the sleeves. Used the long hold down rods from my milling machine clamp set to tie the ram carrier to the base. Sleeves and other bits from stock.
Pulled the joints out with no great effort. Certainly the way to go. Shoulda made a note of the sleeve and pusher sizes needed for other folk. Besides the aforementioned G-Clamp set I have a 32 piece bearing race / seal installation kit and a 36 piece universal pull & press kit about the place so, having plenty to choose from, I tend to forget how much harder it is for normal (sane) folk lacking the toolaholic packrat genes. Prolly about £50 to replicate my knock off, complete with E-Bay sourced ram, if I knew the size of sleeve to make.
I really don't think the extortionately priced Laser Tools ET6293 (https://www.shop4autoparts.net/tools/land-rover-tools/ET6293-BALL-JOINT-REMOVAL-TOOL-DISCOVERY-2-RANGE-ROVER-P38-6293/) is up to the job. After discovering that their front radius arm bush tool kit doesn't, and can't, fit I'm off Laser for life anyway.
Considering alternatives the BMW 3 series ball joint kit E-Bay 123519400770 looks seriously husky but obviously the sleeves will be the wrong size and suitable P38 size ones will have to be made or found. The twin side rods give a balanced pull so it ought to work better than the offset G-clamp type.
The major risk when doing steering knuckle ball joints is that the ABS sensor won't come out needing to be destroyed before the hub can be pulled out. Both mine had to be destroyed. Ended up machining the old tension bushes out on the Bridgeport. Even with my big playroom toybox that gave me some worries. Ordinary guy on the drive would be totally stuffed. Odds are the hub unit is well fretted in too. I was glad I'd kept the scrap disks when I replaced mine a couple or three years back as it gave me something I could safely hit without worrying about damage. Broke one!