Some Lubuntu users may wish to switch their systems to Linux Mint. Tutorials on doing this are outdated and/or don’t provide details on doing this while preserving the existing system. This is how I’ve done it, with great results every time…

create/revise /etc/apt/sources.list.d/official-package-repositories.list with these lines:

deb http://packages.linuxmint.com una main upstream import backport
deb http://archive.ubuntu.com/ubuntu focal main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu focal-updates main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu focal-backports main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu/ focal-security main restricted universe multiverse
deb http://archive.canonical.com/ubuntu/ focal partner

comment out active entries in /etc/apt/sources.list

sudo apt-get update

this will give an error. Take the PUBKEY number and use it instead of the last argument in this command:

sudo apt-key adv –recv-keys –keyserver keyserver.ubuntu.com A6616109451BBBF2

now do this again…

sudo apt-get update

sudo apt-get dist-upgrade

this updates /etc/issue and /etc/issue.net to a Mint name via base-files package

Install these:

mint-meta-core
mint-meta-codecs
mint-meta-cinnamon

check what it installs. Get these if not included already:

    mintmenu
    mintlocale
    lightdm
    # if prompted, switch to lightdm instead of other display managers
    chromium

    mint-info-cinnamon
    # if you get an error during install...
    # may need to download the mint-info-cinnamon (all) .deb from https://packages.linuxmint.com
    # and install using 
    sudo dpkg -i --force-all mint-info-cinnamon_2021.11.18_all.deb
    # due to a conflict with mint-info-xfce

reboot

To get APT completely ready for future upgrades, create the file:  /etc/apt/preferences.d/official-package-repositories.pref

…and enter the following content in it, then save:

Package: *
Pin: origin live.linuxmint.com
Pin-Priority: 750

Package: *
Pin: release o=linuxmint,c=upstream
Pin-Priority: 700

Package: *
Pin: release o=LP-PPA-linuxmint-daily-build-team-daily-builds
Pin-Priority: 700

Then proceed to upgrade “una” to “vanessa” if you want (Instructions on how to upgrade arrived in August 2022).