Its a public testbuild. And since its a testbuild there is a command to gain PL. Dunno what yo think of getting from it since there are no transforamtion effects though but i can tell you how to use it.
1.) Make a server, open the console and type in sv_cheats 1
2.) Type restart into the console
3.) When back in the game open the console again and type in powerlevel X
Replace the X with the number you want.
So Powerlevel 2000000 would set your PL to 2 million.
But as said no transformation effects so youll just see the model change to what its supposed to.