To break it down, first you start with the dog’s bed or mat. Sit near the bed and toss a treat on the bed. When the dog touches the bed even if it is just his mouth to eat the treat you will click. His reward following the click is the treat off the bed. Repeat several times.
Then you will want to build up to the dog standing, then sitting and then laying on the bed (which you will most likely have to give the down command for him to comply).
You will add the command when he is on the bed and is staying on the bed for more than a few seconds.
Then you will start to add in “stay”. Take one step away from the dog on the bed, return to dog, click and treat. Slowly increase the amount of steps and the amount of time before returning to the dog. When your dog is very reliable, step out of the room and return back immediately to the dog, click and treat. Remember to release the dog before he releases himself from the stay position.
If your dog breaks the stay, just ignore it. Return the dog to the mat and start again.