I have a set of hair clippers that work well, but the blades are dull. Can I replace or sharpen just the blades and how?
You need to get a sharpener! Not sure what they run but they make strap types you run the blade back and forth on. Plus, they make some that are electric.
You can replace the blades, buy a sharpener, or depending on the brand you can ship them off to get sharpened.