Is there a way to edit xfce4 autostart applications in a terminal?

I'm using xfce4 as desktop environment on my arch-linux machine and recently made the decision to replace the window manager (xfwm4) and give xmonad a try. I followed this guide and downloaded the functional .xmonad.hs example from github. Now when logging in I am presented a blank desktop and the only thing showing up to me is the xfce-context menu on right-mouse-click. The keybindings don't work either.

To get back to the old behaviour I want to delete the autostart entry xmonad --replace but I can not open any window. So is there a way to do this from outside the X11 session via command line?

When deleting xfce4 and xmonad via pacman the configuration is kept somewhere, because after a new install I instantly got the same behaviour.