Mt Fuji 5th Station to Shinjuku

I am planning to visit Mt Fuji 5th Station in mid Nov. Would like to know if the highway bus is the only way to travel back from 5th station.
Please let me know if there is another alternative and how can I make reservations in advance.

Thanks.

et

Would like to know if the highway bus is the only way to travel back from 5th station.

There are no highway buses going to the 5th Station after November 3! The only buses to the 5th Station in mid November are regular buses, which operate between Kawaguchiko Station and the 5th Station. Reservations are not possible on these buses.

How to get to Kawaguchiko:
http://www.japan-guide.com/e/e6905.html

Timetable of buses to the 5th Station:
http://www.japan-guide.com/bus/fuji.html