I haven't had any luck in the past using that trick where you put a tube from the bleed screw into a jar of brake fluid. When I tried it, the air just got sucked into the caliper through the threads of the bleed screw when it was opened.
I use the method of prying the pads back and letting the fluid level rise in the master cylinder reservoir.
I'm looking forward to hearing what you find regarding removal of the rear calipers.
Experience is something you don't get until just after you need it.