risiOS is merging with Nobara Linux in lieu of a 39 release. This guide is for people who need to upgrade now, or don't like some of the tweaks in Nobara and wish to switch to Ultramarine.
It's as easy as running
bash <(curl -s https://ultramarine-linux.org/migrate-risi.sh)
Sit back and relax, because this will take a while.
Enjoy Ultramarine Linux!