Hopefully someone here can help me out. I've looked in the documentation for XOOPS on your FAQ and other pages, and attempted to follow it two times but the upgrade failed both times. There are a few things these guides do not cover and it's giving me alot of trouble.

Can anyone give me a definitive guide on upgrading xoops? As far as I know there is no patch to upgrade from 2.0.9.2/3 to XOOPS 2.0.13, only a full install. Can anyone shine some light on how to do this?

Or alternatively, is there a way to transfer a mySQL database into a fresh installation of XOOPS so we can keep users, news posts, ect, and if so, what would be the best to way to go about this?

This upgrade to V2.2 FAQ has a list of patches to apply.
If you would have troubles with it, specify what errors you get in which step.

... and the best start is a backup.