Ford F 150 Clutch Master Cylinder?

I'm replacing the master cylinder. Are there any tricks to putting the pin in? It's started, but can't get it to go through.
I think I need to hold the line in with one hand, while holding the unit itself onto something solid, and tapping it with a hammer. BUT WAIT! That's three hands?

You may be making the process a bit more difficult that it should be. Check out either the www.autozone.com/repairs website (free after sign-up) or this link: http://www.ehow.com/...f150.html#