NOTE: These are my notes from a generic fuel injection book.  Readings are approximate.  I have not done these procedures, but they sound reasonable to me.  Corrections and updates would be appreciated.

You will be working with gasoline, the most dangerous common substance on the planet.  Vapors can ignite from a spark or ember several feet away from the source of gasoline and it doesn't just burn, it bursts into flame explosively.  Don't screw around.  Be safe.  THINK.  It's best to have an extra set of hands and an extra brain around - preferably an aware one.  A fire extinguisher is an excellent idea, too.  Vaguely related side trip.

When finished, disconnect the tee & gauge assembly and reconnect the fuel supply line using the barbed connector and two clamps.  Make sure the fuel return line is securely installed.