I clicked no when asked if I received the American Opportunity credit but it still applied it to my tax return. How do I remove it?

It doesn't ask if you want the American Opportunity credit (AOC). it only asks if you have received it in the past. 

What is it you're trying to accomplish.  If you don't want an education credit, just delete the 1098-T. The 1098-T is only an informational document. The numbers on it are not required to be entered onto your tax return. 

However receipt of a 1098-T frequently means you are either eligible for a tuition credit or possibly your student has taxable scholarship income. 

If you claim the tuition credit, you do need to report that you got one or that you qualify for an exception (the TurboTax interview will handle this).