Can I switch my modem there? I think it's hella old, and keeps cutting out on my & throwing me back onto my wireless network.

Of course you can. But you'd be better off to call to have a tech to come out. Tell them your having trouble with it. They'll see that it's obsolete and replace it no charge. I went thru 3 modem exchanges at the store and then had a tech come only to tell me that the one I kept getting was obsolete.

You can get a new one there. I'd call first, though. I've exchanged all my old equipment there.