Edit Official Map / Existing Map
Load game, Click Workshop Create a map, same game-mode, same size Go to the game directory and click on Maps folder C:\Program Files (x86)\Steam\steamapps\common\Unturned\Maps Go into the map you want to copy Copy all the folders, FOLDERS ONLY not the files just the folders Go into the map you created and paste the folders Tab back into the game and load the map you created Profit
By the way, you don't need to close the game, you can keep it open.
Useful Map Edit Links
Unturned Map Editor Guide By Skypirinha
Unturned Map Editor - Zombie Loot Table Options By Drew
Unturned Map Editor Tutorial: Roads Updated