I beg to differ with everyone here who has said "This
is how to do it." How to do it is going to depend on the rest of the story. There is no One True Way to write a fight scene.
Sometimes what works is to describe it in careful choreographic detail — "He stepped to his left and threw a right cross that took the taller man on the point of the jaw. He dropped like a rock." or "They separated and came at him from three directions, the one to his left crouched low, with his knife held out — a street fighter's stance; the one to his right danced back and forth, just out of reach. The final one, the shortest and slightest, stood in front of him, gently swinging the crowbar in his hand to and fro."
Sometimes that won't work and you want to emphasize the chaos. "There were noises and bodies everywhere then, the smack of fists against flesh, yells and grunts of effort and yips and cries of pain; people moving in all directions, clumps of bodies forming then breaking up, leaving one or more on the ground with their dissolution. Then suddenly it was over. Still. Quiet, except for the sound of pain from a few of the shapes on the ground."
Sometimes you want first-person experience: "His fist crashed into my face and everything went red. ..."
Write what works for the story.
...if you don’t love you’re dead, and if you do, they’ll kill you for it.