I've done it the old fashioned ant hill way but simmering is a whole lot faster and works way better. Every taxidermist I talked with advised not to boil, just a low simmer. They all also recommended not using bleach, it deteriorates the bone. I just finished one and did it from start to finish in a day. Once I got the meat loose and completely removed I added fresh water and Dawn with bleach alternative and slow simmered again. Keep changing the water every so often until the water stays clear. Also, make sure to remove all of the brain matter beforehand. It holds a ton of grease and if not removed will cause the skull to yellow. I put a coat hanger through from the vertebrae entrance and "souped it up", then rinsed it out really good with a hose.
All I have left to do is whiten mine using Salon40(40%peroxide) and whitening paste, available at any beauty supply store for less than $10. The 40% peroxide is mixed with the powder to make a paste and is then painted on. Sit in the sun or a warm spot, let it dry well, and then rinse. If it's not white enough to suit you repeat the process. Make sure none of the mix gets on the horns, it'll whiten them too. Done this way the Euro mount should stay white and last forever.