Hi there James,
There was no option to upgrade my database (and I had already read the information in your link before I submitted a ticket).
Once version 5 is activated, you will be prompted to upgrade your database.Please make sure you have backed up your database before running this tool.
There is no prompt, and I have tried deleting both version and trying again to no avail.
I guess I need to delete the old fields and plugin, then install v5 and start again?
Guy