It takes a special attachment to sharpen these blades and isn't something that can be done with just a file or sharpening stone. The blades have to be sharpened evenly all around. It's best to have it done professionally. There is no easy way to do it.
Rival slicer blades can be easily removed with minimal work. Just pick up a sharpening tool at Home Depot or Ace Hardware and you'll be done in two minutes.
