I boiled it for about 30 minutes one night and got as much meat off as I could. Then I stuck it in a bucket of water for about 5 days. Then I boiled it again another day until I got all the meat off.

After that I soaked it in Dawn dish detergent and ammonia for 5 days to degrease then sat it out in the sun to dry. After that I used a bleach powder and peroxide paste to whiten the skull. Fairly simple and it turned out great I think.