Upgrading to PHPWebsite .9x

I run a fish club website, built around a phpwebsite framework. The software recently underwent a major upgrade, so I finally decided to try to update one of them to the new version. A lot has changed apparently, but I followed the directions carefully.

It was a complete disaster. It was as if I had hacked my own site! The database structure is now different, and fields were missing, names were wrong, and permissions got screwed up and seemingly could not be fixed (I have no idea why). I have not been able to find a reliable upgrade path described online. Fortunately, I had it backed up, and reinstalled the older version.

If anyone has a for-sure method of upgrading to the new version, let me know!