I used a card business card on either side of the disc slid into the calliper, then pulled on the brake lever then turned up the bolts.
Normally I just brake, nip it up and then release the lever, spin wheel, then brake a again while using a torque wrench without moving the calliper.
Sometimes the torque on the bolts can move the callipers.
Having a pal hold the brake lever or rope, freeing a hand to hold the calliper too while you nip up the bolts.
Callipers with massive holes for the screws allows too much movement.
Sometimes it’s a few seconds to sort and sometimes a bloody hour.