Doesn't have to be removed for cleaning. I'm assuming you have the entire VES valve out of both sides, of course. Wipe up nicely under the bellows, it will easily lift, just be gentle, use green scotchbrite on the valve itself after getting the big deposits off with a dull blade or wire brush, and you're good. I also use Q-tips for the holes. Make sure they are not plugged. The purpose is really the burnt carbon buildup - that's what really makes them stick, and goo in the passages.
As I recall, it's thread locked on, FWIW. Highly recommend you do not remove, unless you're replacing gillo.