I use a wrench or plier type tool and squeeze the pad against the caliper to depress the pistons.
I can only get the rear by hand the front is too hard for me so I use the above and then they slide out
C6 CORVETTE ZR1
BW C13 - 1:53:7
E92 M3 ZCP
KW CS w/Rs3 - WSIR 1:32:8 / BW C13 1:59:2
APR Wing/Rs3 - WSIR 1:30:9 / BW C13 1:57:7