You can mail your blades to LP Sharp Company and you can exchange your old blades for new ones - must send at least 5 old blades and you can get new ones for $3.00 a blade.
www.lpsharp.com. You can also buy blades for much less then retail even if you do not have trade-in. I have bought from this sight and they work pretty good- the blades you buy are re-sharpend. Check out the web site and they explain how to go about it.