How to train your dog to leave something.
Training a dog to leave it is a difficult job, but it is possible. The first thing you need to do is to have treats that your dog loves! Second, you will need to drop the treat on the ground and tell your dog to leave it. Then, you want to cover the treat with the palm of of your hand if your dog tries to go for it. Keep your hand on top of the treat and keep saying "leave it" until your dog retreats. Next, you want to release the treat and continue the process again. When you notice that your dog is listening and is looking at you then you can allow your dog to eat it. Lastly, you want to praise your dog! This is how you teach your dog to leave it.
(Notice the bold words indicate sequence. I want you to also do that!)