I’m pretty sure there would be no need for pyrotechnics. There is probably a function back deep in admin control that would erase all posts and user accounts, and allow the forum to start anew. Resorting to fire is a waste of good web design.
(also, since this forum is on Amazon Web Services, actually burning the computer the forums are on would spread to the other computers nearby, take down a large section of the Internet, and firmly land you in jail)
If you don’t have access to said kill switch and you actually want to end the forum, the first and most pragmatic approach would be to contact the Aetherlight team and ask them to do so. I would get myself a copy of the Discourse software that we are on so I know what’s there and include the exact technical directions in my appeal so they have no excuse.
I have never contemplated hacking a forum to shreds, this is not a thing I have ever thought about nope nope nope . Not worth the jail time in my opinion. They don’t even give you toothbrushes in jail.