The 4 bleeders are for inventory so you dont have to stock lefts and rights, only use the top bleeders as mounted.
Bench bleed the master. Master in a vice and pump fluid/piston by hand till it flows out the fitting and cap. re-install in car and hook up the lines. Bleed the caliper furthest away from the master starting with the outer bleed screw and then the inner, then go to the next caliper agian the outer screw then the inner. Repeat bleeding sequence of the calipers till you are satisfyed that there is no air left in the system. Leave the bottom bleeder screws alone.