Arch: Migrate Owncloud to Nextcloud

I currently have a RPi 2B acting as a server for my house. It is running Owncloud 9.1.3. Arch and all packages are up to date as of earlier today. I’ve spent some time trying to work out best approach for migration to Nextcloud 11.0.1, which I think is the latest version of Nextcloud (on the Arch AUR).

Currently using Owncloud apps on OSX and IOS for file sharing, contacts and calendar, shared between several devices. The OSX app also automatically backs up data on my OSX machine.

In an Arch environment does is there a clear migration path documented? I’ve found several different approaches but I think that is driven by different distributions in reality. I looked at the ArchWiki that shows how to install, but that looks like a new install to me whereas I need to preserve all my calendar and contacts entries.

Is it as simple as downloading the AUR packages for Nextcloud, contacts and calendar, and installing them?
Can I move straight from Owncloud 9.1.3 to Nextcloud 11.0.1?
I note that Owncloud installs into /usr/share/webapps/owncloud on Arch which seems to be a different location to other distributions, is that a problem if I try to use the automated migration tool (saw mentioned, but now cant find again).