So Adrian, how many fingers left ?
Who won ? The *%$ clip or you ?
I reread my post above and seen it was far from clear.
I used a 13 mm tube wrench because it's outer diameter was a little bit above the shaft one.
So I installed the ring on the wrench (having the wrench in a wise to hold it secure).
Then I put the wrench on the shaft and pushed the little bastard on the shaft. Thanks god it went on easily.
Then using the little screwdriver I pushed it slowly down into it's place.
I had bought two so had three pieces with the old one (badly worn) and I destroyed one, and deformed the second a little upon assembly...
As I said, a PITA...