Are you saying that you can't get the bulb carrier to fit into the new lens? This is common and has a real simple fix. There are a couple of plastic "spikes" coming out out of the lens you just installed, and these spike are supposed to fit into holes in the bulb carrier. (To see what I mean more easily, you can place the bulb carrier on your old lens and see how it fits together.) Now, if you take a look at the new lens and compare it to the old one, you'll see that one of the spikes is in a slightly different location, and since there's no corresponding hole in the bulb carrier, that's why you can't get it back on. The solution is to simply snip off the spike in question.
