I just tanned this years deer hide using the Hide Tanning formula and it wasn't hard at all.
F & T Fur Harvester's Trading Post - Trapper's Hide Tanning Formula
Start with a fresh green hide. Carefully scrap or cut off all meat and fat until the skin is very clean.
If hide is dried soak in plain water long enough to soften.
Salt the flesh side with table salt work plenty of salt into the entire hide.
Fold salted hide flesh to flesh, roll up and leave for 24 hours.
Then scrape off old salt and repeat with clean salt for another 24 hours, then scrape off salt and your ready for the salt bath.
Prepare a salt bath by mixing ½ pound of table salt per gallon of water. Mix salt bath thoroughly and let cool. Immerse hide 6 to 8 hours (except red or gray fox, just 15 min.) Remove rinse in clean water and drain.
Using a sharp knife , thin the skin as much as possible , removing any remaining membrane. (A wire wheel can be used if the skin is allowed to almost dry first).
After the skin is thinned, wash with warm water with liquid dish soap (Dawn) to remove salt and grease . Very greasy skins such as raccoon, beaver, and bear should be washed twice in dish soap to remove all grease.
Then hang to drain.
Warm (Hide Tanning Formula HTF) by sitting bottle in pot of hot tap water for 30 min. The skin should be room temperature, semi dry, but still moist and flexible.
Shake the warmed HTF well and apply an even layer to the flesh side. Apply with paint brush, or by hand wearing rubber gloves, massage firmly into all areas of the skin.
Fold the skin flesh side unto itself and leave over night (12 to 16 hours). After the 12 to 16 hours tanning time, dry slowly over 2 or 3 days. As it dries, periodically pull and stretch the skin until it is completely dry and soft. If the skin is still stiff in spots, dampen those areas with warm water, re-apply warm HTF and repeat.
Note: when the skin is fully tanned it can be further thinned with a wire wheel or course sandpaper. Also pulling the hide over a tight rope will help soften.
Hope this helps