NOTE: Bear in mind by installing this, you will lose access to any of the PSVita exclusive content by converting to the 18+ version.
1. Make sure the Steam version is installed. Once so, pull up it's local files. To do so, right click the game, then click Properties, then click Local Files. You'll see the below. Click 'Browse Local Files'
2. Open up the downloaded zip as well and extract it to anywhere you can find it easily. You should have the following two folders open:
3. Copy the files from the patch window into the game install folder.
4. Click on 'apply patch.bat' - you will see a window like this - it will take some time to run, please be patient
5. You're done!