How often and how difficult is it to grease your trimmers and edgers. I check my filters every day and check the plugs at least once a week but I have never greased anything on them. They get used about as much as my mowers so I know they could use it. I read the manual on how to do this and i'm kind of worried about taking it apart like that. It always seems when I take something apart it doesn't go back together the same. Is it safer to pay the $40 and have the dealer do it? Any help would be good.