First, make sure your Number Lock is on. It's on the top left of your number pad and if it's on, there will probably be a light on the top right of your keyboard (at least that's where mine is).
Hold down the alt key and then type the numbers 167 on the number keypad on the right side of your keyboard. That will make the degree sign... º
Then type the number zero or a capital 'O' .
Then make another degree sign.
ºOº