Drain gas pipe for front tanks
Remove the guard for the rear gas tank.
Close the lower valve for fuel filler pipe using an Allen key.
Shut the valves on the front gas tanks.
Disconnect the connector.
Carefully disconnect the connector for the fuel filler pipe in the rear gas tank. Allow the gas to hiss out. Use an extraction fan or carry out the operation outdoors.
CAUTION:
Beware of any risk of explosion.