I don't!
I bragged when Tatum was a pup that she would let me do it with no problems at all but all of a sudden (and no, nothing traumatic happened), she wouldn't let me. Most of you here know what I mean by the horrible squirming and fighting they can do when you try so I just don't try anymore. She lets me do absolutely anything else but just not that. She seems to wear hers down enough that they aren't a problem and other than that, the groomer takes care of it. We don't go to the groomer on a very regular basis because I keep her hair long and layered but that's where she gets them done.