The full skull is actually called a European mount. There is a vast amount of info and tips out there. Here is just one site I found real quick.
You can use hydrogen peroxide or bleach. The guy that did mine has used both. The bleach he uses is some kind of special commercial bleach. I have them both ways and they each have their own character.
You can also use magnesium carbonate, it's not high priced and you mix it with the hydrogen peroxide per instructions. Make a paste and apply with an old tooth brush, when dry rinse off and set in the sun for a few days. BOOM your done, time to mount....then enjoy.