Throw it on a stone and sharpen it, take your time and watch your angles it's not that hard. If you're unsure of the angles start with about 20-22 degrees or so (total), take a square of paper and fold it corner to corner three times, the resulting angle will be roughly 11 degrees and you can use that to guesstimate your angle on each side. There is a thread on here someplace describing how to use a very fine sand paper on a mouse pad to create a convex edge but is probably all you need to touch up the factory edge on a new blade. As my Dad was fond of saying "you'll never learn any younger".