NAV Server Setup (Existing SQL Server Database)

Hello guys, first post here and i want to apologize for any incovenience i may create.

We are migrating our Navision Environment to a new datacenter and we want to follow the best practices regarding Windows Server, SQLServer as well.

Everything is setup and i could not find any guide explaining on how i could do the setup using the SQL Server database from the old server to the new.

The old environment consist in

Two databases runing under the same Nav Server each database has its own NAV instance.

The new one consists in;

two rds servers with NAV Client in a loadbalancer, two SQL Servers 2012 running SQL Server Always on and its best practices and two loadbalanced NAV Server.

The main question is;

How can i Setup the nav server to USE the old database files restored in the SQL server.

Oh we are using Windows Server 2012 R2, SQL Server 2012 Enterprise and NAV 2013 (not R2)

Any answer that could point me to the right direction will be well received.