I’ve done NP Protons and SS Nanos, effectively both the same inside – it was a while ago though. Bushings just tapped out with a small screwdriver. If I recall the bushings are split so it’s not a tight fit or anything. Pretty sure they come out on the outside of the pedal. The bolt holding everything in is 8mm I think, I needed a long socket to get at it as it’s quite deep inside. There are two 6mm hex dust caps that screw into the pedal body, the internal one is actually there to hold the bearings in place, bear that in mind when you tighten everything down on the spindle because there’ll still be a load of play in there before you put the first dust cap back in, that’s normal.
I might have misremembered some of that so don’t take it as gospel, but in general it wasn’t hard to strip and rebuild them – just go carefully and you’ll be fine.