[Darryl Ramm]

There is no hard and fast guide I am aware of for trying to manually undo installs, and I am not sure Avid ever committed stuff will work forwards or backwards across arbitrary versions and they don't provide an uninstaller for core Pro Tools on the Mac. They do have stand alone uninstallers for Avid Link and Cloud Collaboration (which always get uninstalled by me), and some other stuff.

The installers do run a basic preinstall script that deletes a few basic things that hopefully is fine in most cases going forwards or backwards. But maybe one issue is there are multiple different things that folks might install, Pro Tools itself, plugins, drivers, etc. and just remembering all the different stuff that was installed and getting back to exactly what was installed before could be hard. (e.g. if you installed Pro Tools and it updated the default plugins... do you want to leave them updated or roll back to a previous version? or did you install Pro Tools and it did not update the plugins and you want to leave stuff alone?). Or if you installed a HD driver as part of an update do you want to roll that back with Pro Tools or not? There is no simple "right" answer.

Some folks think you need to say remove the Pro Tools.app folder from /Applications before doing an install. You don't need to do that, it's just a waste of time, when you run a Pro Tools installer it does that for you before it lays in the new (or old) version.

But manually trying to do stuff to get back to a previous working state is really the wrong way to do this. You'll never be sure you got absolutely every last thing. The way to really do this is clone your boot drive to a test drive, or have a test drive that is a clean macOS install. And install stuff you want there, test it out and just throw that disk image away if stuff does not work.