It'll take some time. My girls, while they don't exactly come running, will lie down and allow me to fix their hair. I think they realize that it helps but would still rather me not mess with them.
I love the little grooming bands that Des @ GoFetch sells. They are cute in case you don't put in a bow or clip with them, and they hold hair very well. Penny has very fine, silky hair while Riley's is thicker and the bands work great for both.
I have a few of the clasps that Des sells (mentioned above) as well. They are super cute but might be a bit girly for your little guy. I picked up a package of little clips at Walmart to get the girls used to having something up there first. They stay in well so that the furkids can paw at them and rub their heads without knocking out a hair clip... and eating it!