@senectus Why should it be more complicated than dnf group install […] and maybe dnf group uninstall […]?

Last time I installed multiple DEs, it was as easy as installing them and picking which one I'd like to use from the login manager.

Granted, this was a decade ago. I can't imagine it would be any harder these days.

I would do a fresh install with careful home dir migration. Only take the folders you need but back up your entire home just in case.