With all due respect, this answer just doesn't do it for me. I have come across players who really worked on range, and practiced their tails off to no avail; if you have bad chops habits, all you are going to accomplish with more practice is to continue to struggle with the upper register, and the bad habits will be reinforced. I believe that for some people, it won't ever be easy. There are some who are blessed with it an have never had to worry about it. Then there are people like me who have always had to work on it and practice for the sake of practice is not the answer.