'Tight' is one mother of an understatement when it comes to the ball joint. And on the 530i, the pin sits so far from the edge of the steering knuckle that the normal 'universal' ball joint separator won't reach the tip. But i tried anyway, and set the remover to bear on the lip of the nut. Unfortunately the bang I heard after cranking and cranking was the separator pin shearing cleanly into three pieces.
So here's what I did, and I recommend it to anyone who gets stuck and frustrated and is thinking of getting that custom, ZDMak $200 BMW e39 tool. Remove the main control arm bolt and lower the arm, fully remove the pinch bolt (to get the sensor wire bracket out of the way), note the spacing and crank out / release the steering tie-rod link, and remove the brake caliper and the anti-lock sensor wire. Assuming you've already disconnected the sway bar drop link & thrust arm inner bushing, this'll drop the entire knuckle c/w brake rotor, control arms & steering tie rod in one not-too-hefty piece. Stick it in a secure mount, get a BFH, and knock the damn thrust pin out, along with the steel sleeve of course. You can remove the sleeve with a simple adjustable puller or pickle fork (and it'll come off the pin with that bang you've been anxiously awaiting!). To reinstall the sleeve, I simply squeezed it back into the knuckle using a bolt/spacer/washer set-up.
Re-assembly took about 15 minutes, caliper and all. After spending a full day on the driver's side, needless to say I will not even consider trying to crank out the other side with another lame, Grade-5 steel 'universal' tool. And if you're real careful with the steering link, the alignment won't get screwed.