I have ONLY used a screwdriver. Wedge it between one of the small bolts that hold the clutch to the pulley, and the shaft, then loosen the nut. On the E36 and E46, this is pretty easy to do from the bottom. I have not done it on my X5 yet.

Not too bad. Soaked it in penetrate for a bit, and it came right off. I did back up the bolts with a screwdriver, but could've just held the pulley with my hand.

That nut gets tighter as the engine runs, which is why the threads are reversed, so you do not have to tighten it more than finger tight. The torque spec on that nut is inch pounds, and not very many of them. My memory is 22 inch pounds, which is less than 2 foot pounds.

So. I guess it's good it broke. I have a fairly significant coolant leak from that small silver radiator on the passenger side, towards the bottom of the actual radiator... At least that's what it looks like. I'll post a pic in a minute..

Transmission oil cooler.

So it's the trans cooler? Awesome.

If it's leaking coolant, could it be an o-ring? Any DIY's on it?

Mine seemed to be coming from there but was the waterpump.

When you take that off, coolant is going to drain, so don't do it in the living room else the Mrs. might be annoyed with you.

Aren't there metal clips that are about the diameter of a paper clip and have a small plastic handle on them that you can pull.

Taking that radiator (trans cooler) off should not take a direction booklet. Yes, there are o-rings on the fittings.