How to modify existing level
Editing existing level
Opening existing level
Open existing maps from File > Maps and double click the map you want to edit from the list.
Once you are happy with your changes save them by pressing Ctrl+S or File > Save Map.
Save the map into data/mission/missionname folder where the "missionname" is your mission name. Make sure that your level gets saved into "missionname" folder and the file name is "missionname.fbe".
Example: If you would like to do a mission: "mymission", save it into: data/mission/mymission/mymission.fbe
Basic editor controls
Basic controls in editor
Check page: Editor basic controls