Back up important data
Open a terminal
Update package lists: `sudo apt update`
Upgrade installed packages: `sudo apt upgrade -y`
Perform a full upgrade: `sudo apt full-upgrade -y`
Remove unused packages: `sudo apt autoremove -y`
Reboot if needed: `sudo reboot`
To upgrade to a new Ubuntu release, install the upgrader if needed: `sudo apt install update-manager-core`
Start the release upgrade: `sudo do-release-upgrade`
Follow the on-screen prompts
Reboot after the upgrade completes