Ok so I had to change my front brake calipers because both were stuck. In order to bleed the air out of the system, the repair manual says I have to bleed the rear brakes first and that if i only do the front ones the rear brakes cannot be bled again. Seeing that i haven't even touched the rear ones, is this true and would it be necessary to bleed the rear ones as well? I would like to avoid having to get another set of jackstands, and more brake fluid just for this purpose.