I'm not sure i understand your question

I'm not sure i understand your question, do you mean the 2 others missions (official demo) ?
If so, you select the other mission from the 'Mission' menu.
If you mean changing the miami map (from the positioning grid), well you can only change the position that are on it but can't really change the map, that would also mean change the complete map of the level... maybe some day.. :)

Hope i have answered your question.