update draft raspi notes

content/notes/raspberry-pi/index.md

@@ -39,6 +39,40 @@ You can view networks with (no need for _sudo_):
 $ nmcli device wifi list
 ~~~
 
+### Moving to testing (from bookworm)
+
+First of all, upgrade to the latest packages.
+
+~~~console
+$ sudo apt update && sudo apt upgrade
+~~~
+
+Now change the release name (e.g. `bookworm`) to `testing` in `/etc/apt/sources.list`:
+
+~~~
+deb http://deb.debian.org/debian testing main contrib non-free non-free-firmware
+deb http://deb.debian.org/debian-security/ testing-security main contrib non-free non-free-firmware
+deb http://deb.debian.org/debian testing-updates main contrib non-free non-free-firmware
+~~~
+
+Then update step by step.
+
+~~~console
+$ sudo apt update
+$ sudo apt upgrade
+~~~
+
+> Restart services during package upgrades without asking?
+
+Answer with <kbd>Yes</kbd>.
+
+Finish the update:
+
+~~~console
+$ sudo apt full-upgrade
+$ sudo reboot
+~~~
+
 ## Raspberry Pi 3
 
 ## Raspberry Pi 2