I use covs , is there one in Darwin ? , if not repco will have it
The pistons can be real tight sometimes, especially if the boots are stuffed so I usually use brake line clamps on the calipers I'm not doing
Then remove the pads , caliper ( supported) and disc leaving brake line connected to the one I'm going to overhaul, and , with a tray to catch the fluid, pump the pistons out with the brake pedal. Sometimes air isn't enough

