I feel I can get more benefit from American Opportunity Credit but the system recommended me Tuition Deduction. Is there anyway to change which one I choose?

Here is a link to information on how to select the Education credit that you would like to use. Make sure that you meet the qualifications for the credit.

There's a new urban myth among college students that says they can get a $1000 from the government just for filing a tax form. For most of them, they simply aren't eligible. A full time unmarried student, under age 24, even if you don't qualify as a dependent, is only eligible for the refundable portion of the American Opportunity Credit if he supports himself by working. You cannot be supporting yourself on parental support, 529 plans or student loans & grants. You usually must have actually paid tuition, not had it paid by scholarships & grants.  It is usually best if the parent claims that credit. 

You cannot claim a credit if you are, or can be, claimed as a dependent by someone else.

There is a limit of claiming the AOTC a total of four times (4 tax years) per student, whether claimed by the student or his parents.  You may not want to waste one of your 4 on a small credit, this year, if there's a possibility of a larger amount in the future.  Grad students cannot claim the AOTC.