Note: This procedure requires editing a game file; creating a backup copy of the file before proceeding is recommended. Select a map file in the "maps" folder in the game directory (for example, "LowerParadise"). Copy the file to a different directory. Rename the map and put "cus" before the name. (for example, "cusLowerParadise"). Cut and paste the file back into the "Maps" folder. Start the game, go into the options, then select "Custom Maps". The map you copied will appear. Highlight it, then select "Load".