I had a real hard time with mine. I was first using a Dewalt compact impact and no go. Then I bought an air impact (strongest 1/2" one from Harbor Freight). It also did not budge it.
I made tool to hold it still so I could try a breaker bar. The tool bent. I had to beef up the tool and hold it solid while I hit it with the air ratchet before it finally came off... and mine is brand new.
I'll attach a couple pictures of the rev-1 too after it failed. I didn't take a picture of the rev-2 tool yet.