I don't about what exactly you read, but I'm pretty confident most people do not trim their roo's nails. I know I sure don't.
To me, even if you keep chickens as pets, there is something that doesn't seem right about too much handling of roosters. Now, bantams maybe. But my three roosters are fairly standoffish, and two of them are about 10 lbs. If I need to handle them, I do. (though I do like to have them come close to me)
If you're asking how to pick them up, well. There are many different ways, but I usually corner the roo and grab him on both sides of his body, my thumbs above his wings and other fingers near as I can get to his breastbone. If that isn't an option, you could always lure him close to you and swip realllllly quickly at his legs. Of course, if he does have sharp spurs, this could be bad. I have a scar on my palm becuase I didn't take that into account.
Do try and find a food that he really likes. I didn't realize that chickens have favorite foods, but boy does my roo love peanuts! Mostly try and show the rooster that you're not going to harm him or, more importantly, the hens. Win his trust.
Hope this helps