Scrapers are pretty easy to sharpen. Saw blade and most scraper stock will cut with a file. Stand it edge up in a vice and file it for this type of scraper at a 45degree profile. I'd draw file in this case, easier to hold at a 45. while still in the vice hone it like any edge tool, removing the wire edge by running the stone vertical. when you're at a 45 and polished bright, dab a little machine oil, tallow, nose oil, whatever on the edge.
Now you turn a hook with a burnisher. Take a hard steel object, it can be a lot of things, I use the shank of a long shank tap. You hold it on the 45 degree bevel, and slide it forward and back, slowly changing the angle of burnisher to a more perpendicular angle to the blade. You're actually swedging the steel over into a hook. Depending on pressure and angle you can make this hook from very aggressive to very fine. It's not rocket science to figure out how to make the edge you want.
My card scrapers I'll usually roll one edge aggressive, the opposite edge light. Most my scrapers I use freehand, just a piece of sawblade shaped to whatever shape I wish for what I'm trying to scrape. It's a good way to get rid of those crappy modern saws when you replace it with a good vintage one. Or pick saws up at garage sales and cut the blades to shapes you desire.
