I would kick him off in a heartbeat. Send him a letter certified mail, return receipt explaining why he is to remove his property from your farm. Give him a deadline and if it's not done, then take them down yourself. He can bring the sheriff to gather his belongings as they will be at your house. And if he is caught on the property again for any reason, you will have him arrested for trespassing. Hate to see a fllow hunter lose a hunting spot but he is not respecting your requests and being disrespectful.