I use the old pad - the one without the spring clip that fits into the piston - and a large c-clamp to push the piston back. Watch your MC fluid level when retracting the piston.

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12 E70 3.5i xDrive
03 E46 330i ZHP
01 E53 3.0i
98 E36 323is
12 Audi A4 Quattro
79 Triumph Spitfire
73 MGB