James best thing to do would be to go there at 9:30am. They open at 10am but start taking standby appointments from 9:30am. In that way you will get appointment as soon as they open store. If you go late there or you try to book online or over phone, it will be hard to get appointment quickly
Here is a good web post on how. https://www.lifewire.com/make-apple-store-appointment-with-app-1999600
Go online @ Apple southcenter.
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