[Revan]

To uninstall the old hack, you have to run its installer file and delete from there. The new uninstall part does not remove old code, hence why an upgrade is the only possible course of action when an older version is detected.
The reason why uninstall caused SQL errors on showthread was because it calls tables that you have removed.
Also if you could reference to the errors you got at upgrade, the script was throroughly tested and the latest installer version shouldn't contain any more bugs...

This installer is set to echo every last change, so you know EXACTLY whats going on. It modifies the user table, you get a message saying this.
To find to exactly what was changed table wise, you could just pick open the file.
I HAD to make an auto installer because advanced parsing had to be done to convert the rpg_items_options and rpg_battle_options to $vboptions :P
Plus the installer looks good and is cool

To manually remove the old hack, you have to wipe all references to it from the dbase, its too late in the night for me to dig these out :P