[Kube]

PITA the first time. I use one thin blade screwdriver to move the end of the ring away from its seat. Then push another in the opening between the drum and ring that was created in "step #1".

Pry the ring away a little with the screwdriver and put yet another a little "further down the line.
Soon enough you'll be able to grasp the "loose end" of the ring with a locking pliers and pull it out the rest of the way.

Before reinstalling the ring, cut the "other end" in the opposite direction it is currently in so you may use a snap ring plier next time.