I just did the front brakes on our 1990 745, and it was a breeze. They are the Bendix dual piston calipers with ABS. Very easy to do. And, yes, you can just remove the lower bolt that works as a slide pin and pivot the caliper up, out of the way. You can easily rig up a holder, to keep the caliper pivoted up and out of your way by bending up a wire clothes hanger. Hang it from the spring on the shock strut. Or, you can just pull the whole caliper off easily because the upper slide pin floats free and is not attached by a bolt. Use a hanger to hang it from the spring so you don't stress the flexible brake hose by letting the weight of the caliper pull on it.

You want to remove only the bolt that anchors the bottom of the caliper. Don't mess with the bracket which is the thing held on by the hex head bolts.

Beware, on my car, after new rotors and pads, it squealed like the proverbial stuck pig after the new brakes. The blue Permatex anti-squeal paste did nothing. The anti-squeal shims mostly fixed the problem, but there is still a small amount of squeaking on a full stop from low speeds, like pulling into the garage. It was literally deafening and painful before the shims.
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1955 Human, Scott; 1991 745 Turbo, Brunhilde; 1990 745GL, Snuggle Bunny