Well, you can just try to string it lighter to begin with and see how it does. Depending on what strings you have been using and what you convert to, you might be okay. For example, I have been running 120-100-80-60-40 on a fiver and I plan to swap it as you are. I picked up a set that is 105-85-65-50-32. I haven't tried it yet, but I expect it to be close enough.
If that doesn't work well enough for you then, yes, you should be able to get replacement parts from Alembic to convert it. You might have to send some of the old parts to them to be matched up. I would think that removing the adjustable part of the nut and the current bridge or at least saddles would be enough to get replacements cut, but you'll have to check in with Mica to be sure and to get a price.
This has been discussed previously on the boards, but I don't recall the specific details beyond what I have posted. You might try to search the boards to see if you can find any of the older threads.
-bob