Okay, got a new breather tube for my 2000 A4 2.8. It's a long, weird shaped tube! How do you remove/install it? On the ends, it has these "rings of plastic" around the end of the tube (anyone how has replaced this will know what I mean). I tried turning it gently (not wanting to break it), but can't get it off. I tried squeezing it a bit (again, gently) but it didn't budge. Is there some special way to take this off and put the new one on? Thanks!