As the names says this style was and is very popular in Europe, although the methods have changed drastically. In the good ole days the hide was removed and than left outside to rot and self bleach. There are many was and methods to do this and I will go over a few of them. First let me say if you have a Record book skull like a Bear, Mt. Lion, etc. the best way is to let a taxidermist send it out to a place that cleans the skulls with dermestid beetles this is the safest way and you will have no shrinkage. This is the method most museum use on delicate skulls, bones, etc. 

1. Get the hide off the head and cut away all the meat, membrane that you can. 
2. Get a pot large enough to submerge the skull in, or the biggest one you can get your hands on. Don't take your wife/girlfriend best cooking pot this will only cause you more aggravation than you are about to undertake. You will need to do this outside cause it does cause a odor. You will also need some type of fire like a propane burner. 
3. Fill the pot up with water and add Dawn dish detergent (this is a good grease cutter) I also have a taxidermy product in my shop called Sal Soda that I use with the Dawn, but the dawn will work just fine. Bring the water to a boil with the skull submerged, If there are antlers attached to the skull you want to keep them out of the water if possible, cause they will turn color. If they do it is no real big deal they can be touched up with a little stain. 
4. Every 15 minutes or so take the skull out, BE CAREFUL it will be hot and there will be hot water trapped inside. Now take a semi dull knife and start scraping everything off the skull. This is very time consuming work but is very important. When you have got off everything that wants to come off stick it back into the pot and repeat this process until the skull is CLEAN and I mean clean if you leave any thing it will draw bugs and you know what the little lady will say about what you can do with your skull. 
5. If you loose any teeth in the process let the water cool and poor it out through a screen and super glue them back in. Once I am done cleaning I usually but a small amount of super glue on the inside of the teeth just to make sure they are stable. 
6. What I do next is just a precaution step in case I missed something I could not reach or see. I pack Borax (get this at the local grocery store) in everyplace I can and rub it all over the skull and let it sit over night, than shake it out and rinse under cool water. 
7. Now the next step is a chemical process and most chemicals are not going to be available to the public. I mix magnesium carbonate and volume 40 peroxide and paint it onto a skull and let sit over night. Once dry I rinse it off with cool water, if needed I repeat this step. I have never done it more than twice, this stuff really is pretty strong. 
8. Since theses chemicals are for taxidermy use they are not going to be available without a Lic. If you are interested in small Quantities Email me. 
9. There are other methods that I have never used but have been told work but not as well as the above process. Soak skull in peroxide overnight and than sit out in the sun, or you can always paint it white. 
10. The next thing I like to do is seal the skull, I do this by spraying a gloss or satin coat of clear acrylic. I use the  Krylon brand and it can be found in most any paint store. 
11. The final step is if desired is to attached it on a plaque. I usually sit the skull on a belt sander so I have a flat surface sitting on the plaque and than run a drywall screw from the back.