As usual, to avoid downloading BF4 beta multiple times on our limited Lebanese connection, or if you are giving the files to a friend to skip the download here what you need to do, I just tried it on my brother's PC and it worked:
1- Run Origin and press Preload, let it download for a minute or two until "Battlefield 4 Beta" folder is created in Origin Games folder.
2- Pause update.
3- Exit Origin and make sure its not running in the background.
4- Delete the "Battlefield 4 Beta" folder from your Origin Games folder and copy paste the 5.5 GB one you already downloaded.
5- Open notepad and paste the below:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\EA Games\Battlefield 4 Beta]
"GDFBinary"="C:\\Program Files (x86)\\Origin Games\\Battlefield 4 Beta\\GDFBinary_en_US.dll"
"GameExplorer"="{EB683191-E17C-4062-AE74-656EEE4B329B}"
"DisplayName"="Battlefield 4™ Beta"
"Locale"="en_US"
"Product GUID"="{CFAB3721-549D-4827-A4E8-7F90192114AB}"
"Install Dir"="C:\\Program Files (x86)\\Origin Games\\Battlefield 4 Beta\\"
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\EA Games\Battlefield 4 Beta\InstallOptSelect]
"InstallPB"="1"
@="1"
Make sure to edit the game path to meet yours the one above is the default, save this as bf4.reg or anything *.reg.
6- Run the bf4.reg and click yes.
7- Open Origin and go to your games, right click on Battlefield 4 Beta and click Cancel Update.
8- Right Click "Repair Install", wait a couple of minutes for it to finish.
9- That's it your game is ready.
EDIT: I joined the beta (Graphics are set on AUTO and are HIGH), played for about a couple of minutes, didn't like the game much, hated the map (Siege Of Shanghai), left the game, I cant really judge it as it is only one map and the game is beta, but currently I am not really satisfied.