Manual Fan Mode?

I am messing around with my servo for the first time and want to try to calibrate it, the WIKI says it's best to enter manual fan mode, but for the life of me I can find info on how to set fan to manual mode? I searched the forum, page after page, no dice. I know it's simple but the answer eludes me....

I believe you enter a negative number into the temperature. I typically just use the 4-way switch and it is one of the menu options.

dave