With use of Override VPK:
1) NEW AND BEST! Download destroyeer dota 2 patcher. Add -override_vpk in launch preferences (remove “-enable_addons” if you have it).
Open Destroyeer Dota2 Patcher.exe. Press big grey button (patch client), wait until text below it shows up and it is done. You need to repeat this, if Dota 2 fails to launch.
Additional: first blue button – you can change destination folders; second blue button – patcher info.
2) Download Dota2Changer. Put files from Dota2Changer ENG folder into steam/SteamApps/common/dota 2 beta/dota. Launch Dota 2 Changer [ENG].exe and press YES.
You need to launch UpdaterEng.exe after every Dota 2 update and press YES (it will patch the client and you will be able to use mods agian).
Upload mods files to steam/SteamApps/common/dota 2 beta/dota.
Add -override_vpk in launch preferences.
English video tutorial (made by Shutnik) – press here.
3) You can still use -override_vpk, but you will not be able to find a match yourself. You need to be in a party with someone who does not use -override_vpk and he has to search for match.
Other methods:
1) Modder Shutnik made a great tutorial how on to use injector (it will manually override VPK): English/Russian. You need to rerun injector after every Dota 2 update. You can download the injector here.
2) HUDs, icons, VO, sound scripts, music scripts, flash videos and sounds work with new -enable_addons command (see below).
Do not forget that new destination folder for mods (without using VPK) is steam/steamapps/common/dota 2 beta/dota/files.