Many thanks indeed!
As I suspected, just the same as the callipers on my bikes. The schematic is wrong though, the pad retaining pins screw in from the inside face of the calliper body, not the outside face.
Past (expensive) experience suggests the steel pin will have corroded into the alloy calliper body so an impact drive is needed. I don't have one!
Over to Tim Ayrs at New Elms I think.
Or should I buy an impact driver...?
