General, You don't do the folders properties, if you've got a shortcut to blockland on your desktop, you right click that and go to properties, boom you're on the right window. Also nice tutorial it helped me get back to mapping (I havent played Blockland in months)
For you guys that don't know how to delete grass, go into the World Editor mode, open up MissionGroup- SimGroup and delete all the fxGrass subtitles (Click on one then Ctrl-X)