How do you get a Allen Roth ceiling fan to reverse its blade rotation if there is no exterior switch like most ceiling fans that do not have a remote control?

There IS a switch on the exterior, but it is hard to find. It should be near to the top of the fan (not the pole it is hanging off of). It is this way on mine but yours could be of different design so you may want to check the inside of the fan if you can not find it (it sounds ridiculous but where else could it be?)