Fitting outer CV joints to driveshafts.

I'm in the process of rebuilding a set of driveshafts for my top change conversion. I've stripped them down, cleaned them up including the bearings and have them all ready to reassemble. However, I just can't seem to get the outer CV joints onto the shafts without crunching up that stupid snap ring/ jump ring design that Fiat used instead of a proper circlip.

I've rebuilt a set before and don't recall it being such an issue. There's that metal sleeve that you slide over the snap ring to hold it in place and compress it, and then I seem to remember that you just held the shaft in the CV joint (with the ring still compressed), slide it in until the sleeve touched the edge of the CV joint, and then gave it sharp tap. The splined part of the driveshaft would push through the CV joint and the compressed snap ring would 'snap' out once on the other side, securing it in place. This time I just can't seem to get it to do this though, and keep mangling the snap rings (new rings by the way).

Any hints/ tips as to how to get the driveshaft into the CV joint that I might have missed?

When i built mine up I had the same problem with one of them. I had to make it round again as it was out of shap, in the end I used two screwdrivers to push the clip into the groove on the shaft and got my work mate to hit the joint on.