How to Convert Managed Library to a Referenced Library?

I have read some posts in the forum and some relevant chapters from the Aperture training guide, but cannot find a good answer to this question. Please help...

FYI, I am not a professional photographer, just an amateur who likes the added organization capabilities of Aperture over iPhoto.

I began using Aperture 3 last month. I converted my iPhoto library to Aperture 3 and discontinued use of iPhoto. My masters are (I believe) housed in Aperture.

In one short month, the combination of my imported iPhoto library and my newly-imported photos has maxed out the space in my Aperture library.

Here's the plan. In our home, we have a networked server with over 400 GB of space to which I would like to move the majority of my masters, keeping referenced images in Aperture. My goal is to drastically reduce the amount of space my Aperture library is taking up so that I can continue to import lots of photos.

How do I do this? Please note: I have already created a backup vault of the Aperture library on this server, but I understand that it does not include the masters.