Rochajoel was kind enough to explain to you that what you need to do is create a new database and this will give you a new realm. This would require you either install Zeroshell to a HD, USB Drive or to a Compact Flash card. What device are you using to run Zeroshell?
Read the FAQ on storage configuration and devices
http://www.zeroshell.net/eng/faq/storage/#sto.faq2
If you do have a storage device and need a tutorial for creating a database, then just read the first 6 pages of the below tutorial.
http://www.addressplus.net/ZeroShell-WPA-Enterprise.pdf
Good luck.