Use a ceramic sharpening rod or tapered diamond rod sized for the serrations
Match the rod to the bevel side of the serrations
Sharpen each serration individually with a few light strokes
Keep the original factory angle
Work only on the beveled side unless the knife design requires otherwise
Remove burrs with a light pass on the flat side
Clean the blade after sharpening
Test the edge carefully on paper or soft food
Repeat only as needed to avoid wearing down the serrations
Use professional sharpening services if the serrations are very fine or damaged