Scrape, dry and go no further. You have usable rawhide. When your ready to use it, just resoak it, stretch it over your drum frame, secure and let dry.
Making rawhide means just what the word says: Raw Hide. This means you don't do anything to it! Just scrape off every little bit of meat on the flesh side on a fleshing beam or other standard ways. Then cut off the hair, and when it's short, scrape it off with a sharp scraper. Lots of work, this part. Now you have rawhide. Bernard Mason, in the book Camping & Woodcraft, states that "Salt ruins it for rawhide". Preserve your skin by drying or by freezing. I dry mine by nailing them to the barn walls. Once dry, they last for years, and when I need a piece of rawhide, for example for tying my dogsled uprights to the skis, I just soak a piece, cut it into strips, and use.
You can soak the hide in water, or water and ashes, or water and all sorts of other junk if you want to remove the hair more easily. After a while, the hair will fall out. Note, however, that when you use the water soak method, even if you use a stream with running water over your skin, you are beginning the rotting process of the skin, which will make it less resistant. For making really good and strong rawhide, as for making snowshoes, indians here never soak the skin, because the leather is much weaker.
To thin down the skin to even thickness, indians here stretch out the wet skin on a stretcher and put it out to freeze at -20 degrees or lower. They then use a scraper which looks a bit like an axe to which is attached a long perpendicular handle, and use it to shave off layers from the flesh side until the skin is the proper thickness. In warmer climates, you do the same thing, but dry scrape it to thickness. Note that the toughest part of the skin is on the hair side, and you don't usually scrape that side, except what is necessary to remove the hair bristles.