can I come to your location to swap out my Arris cable modem for one that has multiple ethernet connections?

Yes, you can return/swap equipment to any store.

Take downtown train 2or 3 to West 96th street

I don't know. CALL.

I am not sure give Spectrum a call first

There offce is on 96th st n broadway or u can call

I have no clue. As previously suggested, call them.

I'm pretty sure you can, give them a call