To install on single player just put the folder titled: "Operation Lion's Gate" in your saves folder and go in and play!

To install multiplayer, put the Operation Lion's Gate folder as the world on your server, then either give 
everyone the "Atherys Ascended+LionsGate resource pack OR you can put this link:
(https://www.dropbox.com/s/9b72pod0g5s15lg/Athery%27s%20Ascended%2BLion%27sGate.zip?dl=1)
in for server resource pack and tell players to enable the server resource pack! (NO SPECTATORS OR MAP WILL BREAK)