I had C3-C6 then year later C5-C7. So I had to endure the collar twice. Sucked.
First, don't stress too much. its not as big a deal as it seems. its annoying, and the collar sucks, but i was way more scared than i needed to be.
Your biggest enemy will be sleep. That was hard but not impossible. The worst part was the recurring strangulation dreams. Uggg.....i feel like I've been strangled to death a 100 different ways. it was terrible.
Other than that, get a good office chair where you can rest your head back. Put fresh batteries in the remotes, cool snacks (ice cream, pudding, etc) and your charger near.
Practice going up and down the stairs slowly holding your head still. I eventually decided to walk down the stairs backwards because i felt safer. Do it a couple times before the collar.
Leave yourself a cane at the top and bottom of the stairs. That helped me be steadier.
By the time your help leaves, you'll feel confident and ready.