as I know that he is far more knowledgeable than I am on these guns, but I know that I did not use a spanner when replacing mine so I will say no... you do not need a special spanner wrench.
In a pinch, I've used a section of old belt and a pipe wrench to remove fill ends from guns without damaging them.
As long as the gun is empty, it shouldnt be difficult as they shouldnt be on there gorilla tight anyway.
All those who believe in psychokinesis, raise my hand.
Good judgment comes from experience; experience usually comes from bad judgment.