I followed instructions:
- In the files /etc/apt/sources.list and /etc/apt/sources.list.d/raspi.list , change every use of the word “stretch” to “buster”.
- In a terminal,
sudo apt update
sudo apt dist-upgrade
- Wait for the upgrade to complete, answering ‘yes’ to any prompt. There may also be a point at which the install pauses while a page of information is shown on the screen – hold the ‘space’ key to scroll through all of this and then hit ‘q’ to continue.
- The update will take anywhere from half an hour to several hours, depending on your network speed. When it completes, reboot your Raspberry Pi.
- When the Pi has rebooted, launch ‘Appearance Settings’ from the main menu, go to the ‘Defaults’ tab, and press whichever ‘Set Defaults’ button is appropriate for your screen size in order to load the new UI theme.
- Buster will have installed several new applications which we do not support. To remove these, open a terminal window and
sudo apt purge timidity lxmusic gnome-disk-utility deluge-gtk evince wicd wicd-gtk clipit usermode gucharmap gnome-system-tools pavucontrol