Ive gotten so good at doing skulls everyone I know brings them to me and I do them for people for a small fee.
I skin the head and remove the lower jaw bone before I begin to boil it, I boil it in water with some liquid detergent, the soap helps cut the grease, I boil it for about 2 1/2 to 3 hours then I take it out and remove as much meat as possible with a knife, fork or whatever, then I boil it for a tad longer then remove it and pressure wash it, I have a pressure washer so that makes it easy for me. The pressure washer will blow all the brain matter and all of the nasal tissue out, works real good on the tuff meat and grissel too, I use a rotary tip on mine. Once its clean
I'll reboil it in a water and peroxide sollution, usually 2 bottles of peroxide or one big one for about 30 minutes. sometimes the nose bones might fall off on the first boil but you can glue them back on after your done. Once it's boiled in the peroxide solution take it out and let it sit in the sun for a day it will be snow white, it will come out like a pro did it. Dont use bleach it's corrosive on the bone. Be careful with the horns they will turn white if they are boiling in the peroxide, you can touch them up with stain afterwards too.