watch this video and notice how he has the bolt C-clamped to the table. That's the only way I could get my ejector/bolt back together. If I had two more arms and hands I think I might could have done it without the clamp. Also, it won't just snap back in, it took a lot of force and I think a tap with the hammer and punch too. Once you get the spring and collar in place and put the lever/bolt pin in, it is easy from then on.
I think some say to cut a piece of beer can and put it under the sight in the dovetail to tighten it up. I used a center punch to tighten a couple of mine.http://www.youtube.com/watch?v=9Gx7-k8W2eA