How to Upgrade to Debian 12 from Debian 11
Step-by-step guide on how to upgrade to Debian 12 Bookworm from Debian 11 Bullseye release with additional instructions. Debian 12 Bookworm is releasing shortly. If you are running Debian 11 Bullseye, you can plan to upgrade your desktop or server now. However, it is recommended that you wait until the first point release, i.e. 12.1 of Debian Bookworm, for critical server upgrades.
DebugPoint has published a tutorial on how to upgrade from Debian 11 Bullseye to Debian 12 Bookworm.