1. First navigate to C:\Program Files\Steam\SteamApps\common\Octodad Dadliest Catch\Content\Workshop and extract zoidbergskin40805809.zip
2. Open up zoidbergskin40805809 that you extracted and go into the content folder and copy the Models folder
3. Navigate to C:\Program Files\Steam\SteamApps\common\Octodad Dadliest Catch\Content\ and backup the Models folder if you want the original Octodad skins back later..
4. Paste the Models folder you copied earlier and overwrite everything
4. Open up Octodad and you will have the Zoidberg Skin everywhere (including the new levels)