there should be an xml file that you open up. It contains instructions on which of your phpbb files to amend. This took me about 45 minutes of careful editing to get it to work, i am quite slow so it may take you 15 minutes or so as the mod suggests. There are 2 files which you need to upload, the rest of the installation takes the form of editing of existing phpbb files.
There is a list of fixes a few pages back, essential fixes for known issued with this modification.
I can testify that this mod, when properly installed, and the fixes applied, works very well.
If you have a vanillia installation of phpbb 3, maybe it would be alot easier for people if they could just download the amended files rather than editing it themselves?
I would be happy to send my amended files to anyone if they need it.
One thing to note, make sure you backup all your files using the ACP>system>backup.
Download this file to your desktop, in the event of you misediting a file, you will be able to restore your phpbb system. It might be worth going on to your database server and dumping that as well in case. I havent used the restore facility yet.