Create a complete backup of your first gameserver database with MYSQL Administrator. If you dont have it, you can download it for free
http://dev.mysql.com/downloads/gui-tools/5.0.html. Install it, then run it, login to your database with your username, password, hostname
Backing up the Database of the first server:
Now go to backup, Create a new project, click on the database name under "Shcemata", and click the right side arrow to add the database to "Backup Content" window. Now click execute backup now.
Create the new database:
Now create the new database you will be using for the 2nd server using Navicat or whatever program you use to manage your databases.
Restoring a clone to a new database:
Now, go back to MYSQL Administrator. Go to "restore". Now Open the backup file you created before. under "TARGET SCHEMA", click "Another Schema". Now change it to the database you just created for the 2nd server. Click under "options" ---> "Create Databases if they dont exist". Now click START RESTORE. Once completed, you have a complete clone of the original server.
Editing Server files:
Now just copy your entire L2j directory of your server files and paste them whereever you want. get a new hexid, and put it into the hexid.txt file. Edit the "GameserverPort" in the server.properties config file. It must be something different then the default first server(Default is 7777, using 7776 will work fine for the 2nd server). Now also set the server to RequestServerID = 2, since your first server will be using 1.
Editing Login server database:Now go to your login server database with Navicat or whatever you use, and find the "gameserver" table, Inside here you should only see only 1 row for your first server. Now add a new row for data and use the following info .
Server id: 2
Hexid: copy and paste the hexid you generated for the 2nd server
host: put a * under the host column.
Now save the table. You should now be able to start the 2nd server using the new database, and should now be able to see 2 servers on the login screen. Hope this helps