dead is dead.. it should all be pruned out ... the dead stuff ..

any leaves.. means the root system is not ... and with a mature root system... you could probably cut it to the ground and it will be near as big by fall ... half at least ...

dad had one over the gutters.. nearly swallowing his driveway.. back in the day.. and had me cut it to 6 inches.... it didnt blink an eye... and came back with a fury ...

i suppose we cant talk you into getting rid this invasive monster???

other than pruning.. there is nothing else.. need be done ...

ken