You could try live traps, but I'm not sure how they would work for fox. I have only helped with coyote trapping (years ago), though the approach would be similar. You have to decide which type trap you wanted to use, as there are several variations on the market. Then you would have to settle on a bait/lure. The guy I trapped with used a paste he made in a blender of raw turkey scraps, then aged so it STANK. He was targeting coyotes, but occaionally caught fox or bobcat. There are a number of books available on the subject as well as a few videos. I have always enjoyed calling them in and so don't try trap them. Not only that, we have anywhere from three to eight cats at a time, and they'd stay in the traps. If you know of a spot he's traveling, such as a hole in a fence, etc, you could set a trap there and try to catch him in passing. Just dig out a hole large enough to contain the trap, set your trap down in it so the trigger pan is about level with the ground, and sift the soil back over it to conceal it. It's not really that complicated, but it's not overly simple either. Surely there are some trappers on here. Maybe they'll chime in.