Disable Services
sudo systemctl disable snapd.service
sudo systemctl disable snapd.socket
sudo systemctl disable snapd.seeded.service
List and remove installed snap packages
sudo snap list
sudo snap remove firefox
sudo snap remove snap-store
(...)
Remove Snap
sudo apt autoremove --purge snapd
sudo rm -rf /var/cache/snapd/
rm -rf ~/snap
Install Firefox
# /etc/apt/preferences.d/firefox-no-snap
Package: firefox*
Pin: release o=Ubuntu*
Pin-Priority: -1
sudo add-apt-repository ppa:mozillateam/ppa
sudo apt install firefox