HOW TO INSTALL MODS
Create Mods folder in XCom2/XComGame and place desired mods into folder. War of the Chosen mods would be put under Xcom2/Xcom2-WarOfTheChosen/XcomGame/
Create a shortcut for ModLauncherWPF.exe from the Xcom2\Binaries\Win64\launcher
Copy XCom2.exe in XCOM 2/Binaries/Win64 and rename copied file to XComGame.exe
Launch the game with ModLauncherWPF.exe shortcut, select the mods you want to play with and hit “PLAY”
The mods on Steam are updated to latest and mirrored on http://catalogue.smods.ru/game/xcom-2/ for those on not playing the Steam version. Nothing wrong with the Nexus mod versions,but not really updated and can cause problems with the Community Highlander which is pretty essential for a majority of the great mods.