Sharpening is the intimidating step, but even a less than perfect sharpening job is better than not sharpening at all. And you'll get better at it each time you do it. To start, find the beveled or angled edge. Anvil pruners, with a single blade that comes down on a flat plate, tend to be beveled on both sides, like a knife, and will need to be sharpened on both sides of the blade.
By-pass pruners have only one beveled edge, that slides over the solid bottom half of the pruners. To sharpen, take your file or stone and lay it almost parallel to the blade, on the beveled side. With pressure on the outer edge of the blade, file all the way around the blade in one direction, away from you, lift and repeat. Don't go back and forth.
Do this a couple of times and you'll start to notice the edge getting nice and shiny and you'll be able to see that the cutting edge has been restored.