Okay, this is not that difficult then. The old heads were stretched over a metal ring and then held in place and tightened by the top hoop and bolts to the lower hoop. You need to remove every thing and get and save the "flesh ring" that the original skin was on. This metal hoop is VERY important. Soak that old held in a tub of water until it becomes limp and get that ring.Check the bearing edge on the drum to make certain that it is smooth and there are no breaks or sharp edges. If there are then use some emory cloth and smooth them. Also check the hoops and make certain that they don't have any sharp edges or raised sharp bumps on them, if there are, then smooth them also. It is these sharp edges that can lead to a head failing. Purchase another goatskin that is at least 6 inches larger in diameter than the ring and soak it in a tub of water until it becomes quite limp. Place this very limp, wet and pliable new goat skin over the drumshell and then put that very important ring that you saved over it and pull the excess skin up all around so that you are capturing that ring in the new skin. replace the top hoop (the one with the bolts in it and allow the excess skin to be wedged between the bearing edge of the drum and the hoop and replace the hardware. You want to keep pulling on the excess skin until the flesh ring is almost level with the top of the bearing edge and tighten all of the bolts so that the skin is securely sandwiched in place and everything is very high on the drum. Pull the excess skin hard enough that there aren't any wrinkles and ripples in the drum head but don't tighten to tune anything at this point. The skin is wet and hasn't tightened yet and is very fragile at this point. Don't trim any of the excess skin at this point and be patient. Allow the skin to dry thoroughly for a few days. (it takes a lot longer to thoroughly dry on the flesh ring, so even though it may seem dry to the touch on the head itself, it could still be very wet or damp on the flesh ring. This is where patience is very important....... let it dry.
Once dry, the skin will feel hard, but it will be terribly out of tune and real low. Now start cranking up the bolts going from side to the opposite side (like tightening lug nuts on a tire) and tap the head about an inch and a half in from the rim towards the center of the drum head until you get exactly the same note at each lug. Then once it is equal all around, in quarter turns of the tuning lugs tune it up to where you want it to be. Then very carefully, you can trim off all of the excess skin flush to the hoop (if you are using a sharp knife, don't cut towards the drum head but away from it towards the hoop , please be very careful here, you don't want to damage your new head.)
This is the best way to do it.