1. Sign in to your Zillow profile and click on My Website
2. Click on Domain / URL
3. Type the domain you own in the box labeled What domain do you want to use?
4. Click on I Own This Domain
5. Click on Want to manage your own DNS?
6. Click on Manage Your DNS
7. Copy the 2 A Records assigned. They'll look something like this:
yourdomain.com : 126.96.36.199 (A record)
www.yourdomain.com : 188.8.131.52 (A record)
8. Save the 2 A Records in your domain registrar account and you're done!