Comment # 51 on bug 94990 from Tobias Klausmann

(In reply to Yann Golanski from comment #50)
> Could some kind soul write a how to modify grub2 configs to add the
> `nouveau.modeset=0` so we could test is that work on our setup?

Add it in /boot/grub2/grub.cfg to the kernel commandline for the kernel you
want to boot, or change the boot config inside grub2 for a oneshot (F12). But
you should have just googled that ;-)