By all means, try the gentler approach. Hauling off and kicking your roo and punching him just makes him think you're a rival.
Aggression in a rooster means he doesn't trust you around the hens. When you go into the pen, go slow. No fast moves. Approach the hens slowly and deliberately so he has no reason to think you mean them harm. If he comes at you, bend down and grab him in a football hold with his head tucked under your arm. Finish your chores carrying him like that.
Make a point of handling him a lot, as well as the hens. Soon he will see that he can trust you. It may not happen real quick, though.
I have a very gentle 12 pound rooster who used to be a vicious biter, liberating generous chunks of flesh from my hands, arms and legs. He came very close to being Christmas dinner two years back. With work, he is now a very gentle roo and completely trustworthy around me and any visitors. And he's very gentle with the hens, too. Good roosters like that are somewhat rare. It would be a shame to make soup out of one too soon.