Update..........
I got one side in!
The way i did it was to use a scratch awl (big thick long type with very pointed end) to position one side of the ring and then a big screwdriver to turn the other side until it mated straight into the splined bore. Then used the stub axle as a drift as Wyn suggested.
I was very pleased with myself and finally thought I could stand tall alongside men such as Johnymd, Sylv and Skiddell, having past the gauntlet.
For the other side, overcondifence or nerves kid in, and all looked to be going well until one side of the ring went past the groove. Tried to rescue it but then ended up with the ring sitting at the bottom of the hole!! The only way to get it out was to break the ring....
Moral of the story, take it slow.... and it CAN be done as others have said.
Thank you guys.