After disengaging the handbrake, I removed the motors on each side - they’re each held on with two small bolts which are easy to get at. Removing the caliper/pad carriers was quite hard namely because I hadn’t got an M14 multi-spline bit and the one I borrowed from a garage-owning friend was a long reach version making the upper one very tight to get at with a universal joint socket wrench. The piston on the passenger side was almost retracted sufficiently to remove everything - I applied a bit of pressure with my thumbs and it went back enough. The driver side was more problematic. I don’t know if I wound the spline (where the motor attaches to) the wrong way - it was dark and I didn’t notice - but the piston almost came out but the rubber seals stayed in place. Winding the spline didn’t do much so a combination of winding the spline and using a piston-winding tool (this “plugs” into the two little indents on the end of the piston) had the desired effect. Before I could get the tool to fit in, I applied a little pressure to the piston and it pushed in enough to allow the space. I was worried as a small amount of fluid came out before I got the piston back in and indeed the brakes were spongy but, after bleeding just that side afterwards, they worked fine.
