The rear caliper carrier is held on with 2x 13mm Bi-Hex"12 point" bolts and the caliper is bolted on with a 12mm bolt x2.
Brake line is of course secured with a banjo bolt with 2 copper washers one wither side of the banjo "obvs"
Removal and refitment is easy I'd recommend you get a new banjo bolt and washers just to eliminate any possibility of leakage..
I replaced my rear calipers after the pads wore to such a degree that they fell out. When I pulled the caliper off the piston was close to getting freedom too!!
As for the bleeding of the rear calipers I just gravity bled them, which some will say is the wrong way to do it, but I don't argue with results

When it came time to swap the brake line between the old and new, I removed the bleed nipple from the new caliper to allow maximum flow and then quickly swapped the line over, making sure the brake fluid was topped up I just let the fluid run in/out of the caliper until the fluid ran out without any bubbles, bleed nipple back in and bobs ya auntie..