Help with installing CV axles held in with a c-clip?

A 1995 Neon is the reason I am posting this, but I have had trouble with it on other cars as well. 

The main question is how do you put enough force on the axle to seat the c-clip without damaging anything else?  The service manual says something like "grip the axle shaft and push into the transmission until the c-clip is fully engaged", but I have tried that with no luck.  I did make sure the c-clip was as close to centered as I could get it and that the splines are lined up but I still can't get it.  I remember doing it before without much trouble but that was 10+ years ago and I will be 40 this year and I just don't think I have the strength anymore. 

How do other people do this who aren't strong enough to just reach up and pop the axle in with one hand?

Apparently the answer is to hit the end of the axle with a dead blow hammer, at least that worked this time.

I am of the opinion that a few hammer taps won't hurt anything, but you have to know when to stop...

I've had an aftermarket/reman axle with a c-clip that was so oversized, it couldn't be installed without damage. I mangled the clip and scarred the splines a little bit trying. I then swapped out the c-clip with the one from the original axle that was the proper size and it worked.

Install into loose knuckle.

Place axle in straight line.

Use a push and pull motion against the knuckle with all your force.

Should seat in under 3 tries.

I have found that aftermarket c clips for neon axles lack a bevel.  I used a grinder to round out the square edges and it seems to work a little better.