This guide assumes you are running Simpleboard 1.1 stable and are upgrading to Joomlaboard 1.1.2!

First complete your upgrade from mambo to joomla (instructions can be found on help.joomla.org)
Back up all simpleboard data in the data_base_ (the prefix is [joomla_prefix]_sb), normally you won't need these... but just to be sure.


Install joomlaboard 1.1.2 and check if everything is working.
Assuming it does set up your forum with the same settings as simpleboard
Copy all avatars (located at /components/com_simpleboard/avatars) to joomlaboard (/components/com_joomlaboard/avatars)
Copy all uploaded files (located at /components/com_simpleboard/uploaded) to joomlaboard
Copy any custom templates to joomlaboard
If everything is working like you'd expect it to: Uninstall Simpleboard 1.1
Note: It's possible you won't be able to copy the files with your ftp client because of ownership issues. If this is the case, use joomlaxplorer.

Upgrade data_base_ in Joomla-board config !