I would think it would be easy, with patience. Others will chime in but heres is what I would do. I'd get a microscope (Radio shack $10) and look to make sure the edge isn't screwed up, that is that it isn't nicked badly. If so, I'd hone until flat. Lap the hone correctly, using wet/dry sand paper. Then simply hone the razor flat with a little pressure and lessen the pressure until it shaves good. Then use less and less pressure until it shaves great. In the event that it is overhoned, just back hone on 8K a little. The process is just playing around using a heal leading stroke in the beginning and working the edge until flat. Read up on honing and play with it. Buy a strop and start stropping. Towards the end keep the strokes the same angle, the same exact length, and the same exact pressure equally on both sides. Use an X pattern at the end. Pretty simple really. If your friend has really screwed it up use the 4K side until its no longer screwed up. Your looking for a nice bevel with which to sharpen on.