If its a ' circlip' circlip then the holes at the end & circlip pliers, but if it's a spring ring like you'd find on an automotive piston then there's nowt to get hold of. They are usually done by pushing one side of the ring & inserting a shim to stop the ring going back in the groove when you let go. Press 1/3 of the way round & pop a shim in, repeat at the next 1/3 way round, pop two in here. Wiggle the shims around so that they are at 12 o' clock, 3,6 &9 as opposed to 12,4 & 8.
The shims should allow the ring to be lifted off.

Shims can be thin feeler gauge leafs, plastic from milk bottles/ packaging or strips from tin/ aluminium cans but watch out they can be like razors.

Never seen a Scorpion in bits so this might not be the way to go, rings can be brittle so flexing or twisting them can snap them........

Good luck