I haven't been there yet myself but based on a couple of other posts I've read, the models are open from 5pm-7pm. They are located in the theater building at SSR. I hope someone who has actually been there will provide a more detailed response.
We didn't make any appointment, we just went there. Tours are every 30minutes on the 15 and 45 minute mark. They are in the theater of SSR but you have to go to the DVC desk I think. Thats what we did. Enjoy.
We were going to play pool one night and it had just opened, so we just walked in and checked out the villas. They are very nice and the third bathroom in the 2 bedroom is very nice. It is in the theater building and open
from 5 to 7.