Very difficult! The instructions from SS don’t relate to the RS gaiter. Much more difficult to dismantle the RS gaiter collar without doing any damage. I bought a second hand set so I could avoid this and keep the original assembly intact for an easy swap back to stock.
Thanks @pnp77. Ill try again this evening. Out of interest, do you remember at the time you put the collar assemble together, onto the leather. Did you have the bottom of the gaitor fitted to the frame at that time?