How do I get rid of ring worm on my head?

I have what looks to be like ringworm its a small red circle on the left side of my head. I think i got it from doing jujitsu Ive had it before when i was in the Marine Corps and i know i used tinactin cause its just a fungus but i dont know if i can just spray it on my head like i did my feet and legs. Before it was because baby wipes only get you so far in the jungle now its from the mats of the gym. Long story short any ideas of what i need to get rid of it????