Am I right in thinking to strip the stanchions out of the lower legs I'll need to undo the hex bolts slightly, then tap them in sharply to release them?
Yes, just screw the bolts out a bit, make sure there is still enough threaded so no to damage the threads, then tap out, shouldn't need to whack them, then obviously take the bolts fully out and remove legs. The bolts bolt into the damper and dummy shaft, so they should still be inside the legs and come out the bottom once the circlips are removed from memory. Really straight forward though.