I'm replacing the tubing on my mini. I 1st removed the little black cover so I could have better access to it. The tubing that was on there was on real tight and from what I can tell it was superglued on. My problem is getting all of the flexible tubing off of the brass nipple in order to have a tight fit. I've got most of it off to where the tubing will slide on to the nipple but just not far enough. Is there a trick to getting that old tubing completely stripped off? And when I put the new tubing on should it be superglued again? Thanks..