Nano Sim card Question

I know this may sound dumb to some, but I should have my new Note 5 by noon, and it has a nano card, I upgraded on one of my other lines that was due an upgrade, but want to use my number not that one, will I have to go into the store to have them change it or can I do that over the phone? I apologize if this is general knowledge but a search got me a zillion answers but not exactly what I was looking for