pamac has a command line reinstall, it also is the gui, when you click
the package needing reinstallation there are remove and reinstall buttons
You could switch to a vt and start networking, then install xfce or icewm or .....
From a terminal some of these have start*, startxfce?, startlxde and so on
Some you have to know, openbox, openbox-session, icewm
All these (when installed) in /usr/bin
With networking functional, pacman works, that's how you install another wm
man pacman for info (in yet another vt)
There is a drop down box in sddm to choose wm, usually upper right
I am assuming you know about virtual terminals and how to switch?
the package needing reinstallation there are remove and reinstall buttons
You could switch to a vt and start networking, then install xfce or icewm or .....
From a terminal some of these have start*, startxfce?, startlxde and so on
Some you have to know, openbox, openbox-session, icewm
All these (when installed) in /usr/bin
With networking functional, pacman works, that's how you install another wm
man pacman for info (in yet another vt)
There is a drop down box in sddm to choose wm, usually upper right
I am assuming you know about virtual terminals and how to switch?