I've had Bu for almost 2 years. When I first got him he was almost a spook. He wouldn't leave his crate willingly for close to 2 months. I would put his leash on his while he was laying down and say either "let's go" or "come". After a few weeks I said "let's go" before I put his leash on and got up and out of his crate. I didn't even realize he knew what I meant until then. So my suggestion, is put a leash on him, use a command of your choice, gently tug until he gets up. It takes time. Even commands that are informal, are taught. My boy know a command "stay here". I used to really use it at my parents, but now use it any time and it works well for us. If I'm in a room with Bu and I don't want him leaving the room or an area, I tell him to "stay here" and he knows not to go anywhere, but the room we are in, is fair game for him to explore. That command probably took us months because it is situational. Patience is very important. Good luck.