Well done Matthew. Pat yourself on the back and pour yourself a beer. I contemplated going down this route when my calliper's piston seized a while back, but took the easier route of buying a refurbed unit from ECP for around £170, after exchanging mine.
I used one of these (or similar) from Machine Mart to help with retracting the pistons:
https://www.machinemart.co.uk/p/lase...e-wind-tool-s/
My symptoms were warm wheels (NSF and OSR), the NSF just needed the pins cleaning and greasing.