After step 4 ( stretch and dry) it will need to be tanned.A skin just dried is what is referred to as " green".You can tan it at home,but shipping it out is probably your best choice.The only tannery that comes to mind right now is,Moyle Mink.You can find them on the Web. On number 3.If you stretch the pelt cased,you need a coyote stretcher.Probably easiest to get a wire one.If you want to go flat,make a cut up the belly from the genitals,right up to the chin.Then, go from the front paws,straight across to the cut up the belly.If the skin were lying on it's back,the cuts would look like a cross.Then get a piece of plywood and use push pins to hold it open.I would start at the nose,right in the tip.Then,pull straight down,and pin the base of the tail.Now you have to open it all up as evenly as is possible.Use as many pins as you have to.They will not hurt the skin.Good luck.
