Actually I think they mean that “as a girl” (meaning the commenter is a girl), they “head cannon” (meaning they use a cannon to shoot heads) “at the arch installation bandit”. I hope this annotated version helps!
I head cannon the arch installation bandit as a girl.
Quaffing the potion of gender stability, now in your female form you strap on the head cannon and fire it at the arch installation bandit.
The arch bandit takes 5d7 damage and collapses prone. Seeing their leader defeated, the subordinate installation bandits flee. You have reclaimed Installation Cathedral from the bandits and can now invite the Installation Medium to summon the spirits of past operating systems.
Recently wanted to try KDE 6 on my second laptop and after being pissed off at the lack of encryption with Void installer (gotta do it manually, have done it in the past but I’m lazy), another fail with NixOs (known bug with encryption in the latest stable installer) the easiest way was installing Arch lol.
I used archinstall as suggested, just answer questions, no manual voodoo incantation required. You can do it.