So, you need :-a brain-Warcraft 3 : The Frozen Throne game-internet-this map, optimized version
Then, you have to put the map file Dragon Age Remake in the Map folder in Warcraft III folder. Here is the logic path :
C:\Program Files (x86)\Warcraft III\Maps\Download
Here you are, you can now host this map in LAN !
But how to host it on Battle.net ?
Even more simple.
Go on this website : Makemehost.com
Choose the latest Dragon Age map in the list, choose a game name and write your Battle.net name for Owner, choose the server and click on "Host MMH".
Copy the game name, paste it in your WC3 Battle.net search bar and wait for others player to join !