Ubuntu PPA
Release notesRemove other clients
If you installed other Bitcoin Cash clients via PPA, it would be better to uninstall those binaries and remove their repository.
Eg to remove abc repository you need to execute these commands:
                sudo apt-get remove bitcoind bitcoin-qt bitcoin-tx 
                sudo add-apt-repository --remove ppa:bitcoin-abc/ppa
              
            Install Bitcoin Cash Node
If on Ubuntu 18.04 bionic, you need to do some extra steps:
                sudo add-apt-repository ppa:ubuntu-toolchain-r/test 
                sudo apt-get update 
                sudo apt-get install g++-7
              
            (all Ubuntus)
                sudo add-apt-repository ppa:bitcoin-cash-node/ppa 
                sudo apt-get update 
                sudo apt-get install bitcoind