When I started lawncare, I took my mower blades to be sharpened at Home Depot. I got a sneak peak at what they do. It's basically a small room in the back with this High School kid who put the blade on his lap, and he used a file to sharpen it. He was done in like a minute or two. No clamps, no eye protection, no gloves, no angle grinder, just a file. You can tell how much you need to file because the edge turns silver. He put his thumb on the edge to check for the burr, and put it on a nail on the wall to check balance. And he did an excellent job (angle grinders take off way more than is needed). After I realized how simple it was, I always did it by myself. I use an impact driver to remove the nut from the mower, get the blade, sharpen it, then put everything back.
I think that's the biggest hurdle with sharpening your own blades: It looks scary/hard, but it's surprisingly easy, cheap, and safe. I got this file awhile back:
https://www.amazon.com/gp/product/B00762JCAY , but they probably have better ones now.
