Throw out alignment.
I don't know if you have looked at 5th Edition much, but what advice would you give for turning that edition of D&D into a Sword & Sorcery game?
People in S&S stories are gray. They are sometimes good and sometimes bad--they are people. Heroes are many times anti-heroes.
Make Monsters monstrous
. Cut down the number of monster encounters. Throw out the super magical beasties, like piercers, mimics, and gelatinous cubes. Have a reason for each beast to exist in the place that it does.
Make Magic mysterious
. Make it rare. Make it dark. Most people should be afraid of magic. It should not be common at all. Take out all the magical traps, potions, spells, and about 99.999% of the magic items. Make mundane items important in your game. If there is a magical item, it is usually more like an epic item, and often it has a severe downside.
Make Combat deadly.
No magical healing. Use herbs and the Heal skill to heal people.
Wounds should heal quickly.
Since this is a game, it is no fun to have a character always low on hit points or unable to adventure because he's out healng. So, increase normal healing a tad. Let mundane things help, like a good meal adding a +1 HP.
Treasure Should Be Spent.
S&S characters don't get rich. The gold they find drips through their fingers like water. Don't allow the PCs to find mountains of coin and jewels. A player should be excited when he finds a bolt of fine cloth that he can sell for a few silver pieces--or maybe he drags around a heavy extra weapon until he can find a buyer.
The Tale is its Own Reward.
D&D is about finding lots of of things all the time--a new magical ring, some new magical boots, new spells, a magical dagger, etc. That's not a S&S game. The pure enjoyment of playing the character is its own reward. Keep the game low magic, low level, and slight on rewards. There are no dungeons with loads of loot hidden within them.