Just turn the black nut on the bottom of the reg counter clockwise, it will slowly go inside the reg as you turn it until the point where it wont turn anymore
Normal pressure should be about 180psi on the gauge
well to see what pressure its at you need to air up the ion anyhow. But turn the black botl at bottom of reg until its all the way in to be safe. Then air up ion and turn bolt the other way until the gauge reads about 160-200.