Check out the Official Level Editor Guide:
https://steamcommunity.com/sharedfiles/filedetails/?id=3466901617
Here's the new level:
https://steamcommunity.com/sharedfiles/filedetails/?id=3487022881
From now on I'll upload new levels to the Workshop first, that way I don't have to do a stand alone build for each new level, and I can get feedback and improve on them before committing to putting them into the main campaign.