Best Buy camera lens exchange

I need to exchange a Nikon lens for another. They are about the same price. The one I want is only available online it says, and it can't be shipped to the store. How can I exchange the lenses? Thank you!

Added (1). I would have rented it. But it was a birthday gift and my mom mistakenly bought the wrong one.

You will not be able to exchange one lens for a different lens. You will need to return your lens (and probably be charged at least a 15% restocking fee), and then purchase the other lens.

That is why I rent lenses for a weekend to make sure it is what I want/need, it is cheaper than paying a restocking fee. For example, if I buy and then return a $500 lens, it is a $75 restocking fee. If I rent the lens for a weekend, it may only cost me $15-$25 (and they deduct the rental fee off of the lens if I buy it when it is returned (the rental or on a new one.