Ok. The process is not long and the process has gotten a lot easier. All your levels must be in the same folder. In there must be bigmap.txt, I hope you know what that is. After all your levels and bigmap.txt are in the same folder open up a level IN THE LEVEL EDITOR and press M. A box will appear and it will go through all the levels relatively fast, after which it will ask you to save the map. Simply save it and your map is made. If you still get a black screen try doing this process from an inside level, I dunno why but it works sometimes.
__________________ Job: A Legend
And you think that you have played Graal forever? Ha!