We had put one of those plastic blade attachments on our "weed eater" a couple years back and it finally wore down to the nubs at the end of last summer. We had replacement blades but I couldn't get the housing off. I finally called the 800 number at CMD Products for the Home and Garden: Grass Gator, Xcalibur, pestNOmore, and BagClips. I expected no help or to talk to a sleepy person in India, but a very suburban america sounding man answered the phone at 7:00 PM my time. "Hold the line spool housing and turn the grass gator to unscrew the set nut," I was told. "Tried that," I said, "The plastic Grass Gator spins around the nut rather than turning it." "Okay, spray it with some WD-40 and try again." I let him know I'd tried that a couple weeks ago, twice. "Okay, I don't want you to mess up your trimmer -- cut the plastic on the Grass Gator, I'll send you a new one, no charge."
Sure enough a new one was in my mailbox 3 days later from California. I used a Dremel type cutter wheel to get rid of the plastic, then a standard socket wrench and 2 people's worth of torque to remove the screw. This new 'Gator is made of a harder plastic so hopefully it will do better at removal when the time comes. But they sent new blades on the new Gator so I'm all set for now. Thanks.