How to install OSM client
From OSM Public Wiki
In those cases where you have an OSM already installed in a remote server, you might still want to operate it from your local computer using the OSM client. In order to install OSM client, you will need a Linux machine and follow the procedure below to install it:
curl http://osm-download.etsi.org/repository/osm/debian/ReleaseFOUR/OSM%20ETSI%20Release%20Key.gpg | sudo apt-key add - sudo add-apt-repository -y "deb [arch=amd64] http://osm-download.etsi.org/repository/osm/debian/ReleaseFOUR stable osmclient" sudo apt-get update sudo apt-get install -y python-osmclient