Summarize:

Fleshing the hide is the process of scraping off the flesh and fat, which prevents the hide from rotting. Place the hide on a fleshing beam (a beam designed to hold the hide in place as you work) or on a tarp on the ground. Use a fleshing blade to scrape off all visible traces of flesh and fat using quick, strong strokes.  Flesh the hide immediately after cutting the hide from the animal's body. If you wait more than a few hours, the hide will begin to decompose, and it will fall apart during the tanning process. Be careful not to damage the hide as you scrape. Don't use a knife not intended to be used for fleshing, since it might puncture or scratch the hide. After fleshing, immediately lay the hide in the shade on a tarp and cover it with three to five pounds of salt. Make sure it is completely coated.  Over the course of a couple of weeks, continue salting the hide until it has become crispy. If you see a pool of liquid emerge from an area of the hide, cover it with more salt. Tanning solution is made from a combination of household ingredients and chemicals you'll need to source elsewhere. Gather the following ingredients:  2 gallons (7.6 L) water 1 1/2 gallons (7.6 L) bran flake water (Make this by boiling 1 1/2 gallons of water and pouring it over a pound of bran flakes. Let the mixture sit for one hour, then strain and reserve the water.) 8 cups salt (not iodized) 1 1/4 cups battery acid 1 box baking soda 2 large trash cans 1 large stick, for stirring and moving hides Begin by soaking the hide in clean water until it is soft and pliable, so it will absorb the tanning chemicals more easily. When the hide is ready to tan, peel off its dried inner skin. Then take the following steps to tan the hide:  Put the salt in a trash can and pour 2 gallons (7.6 L) of boiling water inside. Add the bran flake water and stir until the salt has completely dissolved. Add the battery acid. Make sure you wear gloves and take other precautions to prevent getting burned. Put the hide in the trash can, punching it down with the stick to make sure it is completely covered in liquid. Let it soak for 40 minutes. Fill the second trash can with clean water while the hide is soaking in the tanning solution. After 40 minutes have passed, use the stick to move the hide from the tanning solution to the clean water. Swish it around to wash off the solution. When the water looks dirty, pour it out, refill it with clean water, and wash the hide for another 5 minutes.  If you plan to use the hide to make clothing, add a box of baking soda to the rinse to neutralize the remaining acid. This will prevent the acid from harming people's skin. If you don't plan to use the hide to make clothing, you can forgo the box of baking soda, since in neutralizing the acid it lessens the acid's effectiveness in preserving the hide. Remove the hide from the rinse and hang over a beam to drain. Swab it with neat foot oil to condition the skin. Hang the hide on a stretcher or hide dryer to finish the process. Place it in a place out of the sun to dry.  After a few days the hide should feel dry and flexible. Take it down from the rack and go over the skin side with a wire brush until it has a suede-like appearance.  Let the hide finish drying until it is fully dry, which should take a few more days.
Flesh the hide. Salt the hide. Gather tanning equipment. Tan the hide. Wash the hide. Drain and oil the hide. Stretch the hide.