Ok I FINALLY found a picture of what I am trying to describe.
You will see two of these things (in the yellow circle) on the back of the light. They will be located diagonally across from each other.
Insert the philips screwdriver into the hole in the top (where red arrow is pointing) and turn the screwdriver normally. If you look closely at what you are doing, you will see the cog turning.
One is for Horizontal the other is for Vertical. (I don't know which is which) but you will soon work that out.
