I don't believe you can transfer spots, but you can cancel your current day spots and buy new spots for another day permit if there are available.
They way the permit system works in WW (if I am not mistaken), we have 75 spots per day or 5 launches, whatever comes first. So if 3 launches pay for 25 (max) spots, then that is the max for the day. If there are spots available, then you can increase the spots on your permit (up to 25). If my numbers are incorrect, please let me know.