At first the air hoses and special CO2 hoses can easily be pushed on the connection piece. The hoses harden more and more as the months go on and can only be removed from the connection piece using great force. If you pull the hose hard it will only strain the connection, which could, in the worst case, even break off. Instead cut the hoses you want to remove laterally at the ends and carefully remove them. For this it’s always advisable to install hoses with some reserve in its hose length.