Found on teamliquid. And more info on reddit/battle.net forums.Just go to your Battle.net app's directory. Hold down SHIFT and right-click in an empty space in the directory and go to "Open command window here". In the command prompt, type "battle.net.exe --game=s2_beta --install" without quotes. The SC2 LotV installer will launch as if you had access (obviously you still don't, it just installs the game).
This map can be loaded with SC2Switcher : Cloud Kingdom LE LotV
It has the tooltip of LotV but can't build the new units (afaik).
I'm amazed that nobody on ownedcore is speaking about this already, or trying to created a modded map that'll work with new units.
I won't add all found stuff to this post yet (search reddit/teamliquid if needed), i'll only do so if someone's showing interest.