Double click on the JAJC icon in the System Tray
Click the light bulb button
Navigate to Tools > Accounts > Setup
Account field should be set to Default
Enter your nimbuzz username in the Username field
Enter your nimbuzz password in the Password field
Enter nimbuzz.com in the Server field.
Resource is Just another Jabber client.
Set After connect Stay: to Online
Select the Connection tab
Check the option Connect by IP/hostname
In the IP/hostname field enter nimbuzz.com
The Port number used for IM communication is 5222 and 5223 for encrypted SSL connections.
Check the option to Store all settings locally
If Proxy configuration is required select the Proxy tab and configure.
Press OK.
Next step to is to add contacts from the light bulb icon
To enter any chat room click on join/create groupchat & enter server conference.nimbuzz.com, username- your nimbuzz id, leave password blank, enter the room name to enter
I guess that was easy