The easiest way to re-profile is with a Lansky system using diamond stones and their bench anchored hand grip for leverage...



This gives a precise ability to put a primary and secondary bevel on a knife if you take measurements and work out the angles....you can do a job on these that "mates" up with the angles on a Spyderco Sharp maker and use that to top up your edge and keep it razor sharp. A primary and secondary bevel is as close as you can get to a "convex" edge without needing to use "freehand" techniques.

After a while learning the ropes like this you can get a belt sander and using different belts develop a true convex edge technique which once the tricks are mastered enable a very fast way to re-profile or simply "top up" your edges