At the end of that list, make two new lines cosisting of the following:
SetLevelInfo(300001, DEPRECATED, 0, 0, 0, 0)
SetLevelInfo(300002, DEPRECATED, 0, 0, 0, 0)

Save the file as a lua (not txt) file. Boot the game and you should see it in the Scenarios List.

For this example we will use "scenerio15". Use Notepad to open the hub.lua file in that directory and locate the following string:
Game.SetObjective(OBJECTIVE_WEAKEST_LINK,3000);

Simply replace the 3000 or any number in the "Game.SetObjective ..." string with a more satisfying value and save the file as a .lua file (save not save as). Reboot the game and the changes will take place.