Grab the top of the tiller wheel and move right or left.
 I'm a noobie on this but getting better. Have a question of my own though.  When steering with the tiller the nose wheel angle shows. But after a while (I've looked away) the wheel won't return to 0 degrees. It will go to +4 or -2 or something like that, but not 0. Anyone have an idea?
 Also I can't seem to find a tech support link where I can ask this directly of the "factory".