Should be plug and play.
- Hook up coax line
- Attach network cables (if applicable)
- Power up.
You may need to go through Metrocast's setup. If it's anything like Comcast, it's pretty simple and they include directions.
Again, if it's anything like Comcast, you're paying $10/month to "rent" their modem. You can buy a nice Arris Surfboard DOCSIS 3.0 modem/router from Best Buy for $60 and you own it vs. paying $240 over a 2 year contract period to rent their modem which is typically an Arris Surfboard anyway.