I'm planning to change the front pads on my S4 B8 (2010) replacing the PAGID OEM SPEC with Tarox fast road pads. I'm very handy on the tools and am just after some guidance to prepare for the job by understanding if the pistons push in or screw in? Any gotchas people have found whilst doing this job? I'm replacing them after only a couple of thousand miles because I've experienced poor compound transfer between disc and pad. As a result they vibrate when they get hot under longer breaking loads.