The installation of the game is pretty simple:
Just head to the main website (https://www.beyondallreason.info/download#Download-Play) and download the installer.
Install onto you fastest SSD, so you'll have fast enough loading times to be able to choose a starting position in multiplayer matches.
If you want to move the game directory manually to another location, you also have to change the registry entry for the game.
Otherwise future updates via the game launcher will reinstall the game to the old location!
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\a5671b31-085d-5fba-830a-66a891c6a4a4]
"InstallLocation"="C:\\Spiele\\Beyond-All-Reason"
"KeepShortcuts"="true"
"ShortcutName"="Beyond-All-Reason"
Follow these tips: