And if you want them out in an hour, do number 8
8) Set up loud speakers and play Trump Rally speeches
They would be out in less then an hour
Texaco had an office building in Harvey, Louisiana. Every night the local teenagers would congregate in their parking lot and leave a lot of litter. Texaco tried several different things to discourage their behavior. They finally achieved success when they placed speakers on the roof of the building and played loud classical music all night. The teenagers flushed like a covey of quail and never returned.