I understand that the reasons you are trying to change your age is because you feel as if you have wasted or missed a certain age, or miss the carefree joys of a younger age. I am usually the one to say that nothing is impossible, and nothing is, but it would be best to stay the age you are now. Even if you were able to change your age, such a thing would be quite risky, eh?
I'm not trying to put you down or anything, I would want to know the same thing, but I'm trying to be helpful. Hope this helped. Blessed be~