Is there anything I need to know? I've never done it before and don't want to spray bits I shouldn't.

Do I need to remove any parts before I push the nozzle on the Hammerite Smooth Green and drown the half-stripped parts (see pics)

Ta

do not remove all the existing coating as the parent metal is an alloy, so the coating/paint may not adhere.

I'd mask up the piston and rubber gaiter around it as you don't want paint getting in there, and also the moving lever parts on the back of the caliper for the handbrake assembly.

Completely off topic here Jigger! But....

Just glad to see that the rear carrier guide pins are of a different design, top pin compared to bottom pin. I serviced mine a while back and was a little confused to see that one pin has a stepped diameter design, and one pin has parallel flat. Guess it has something to do with their movement.

With the painting, I'd protect the handbrake mech, the bleed nipples, the pistons and boots, the mating surfaces on the carriers (where they butt up to the hub) and the guide pin holes in the carriers.

Cheers Bodge, so this all looks good to go straight on my Octy then?