The classic method for teaching a dog the Roll Over Command is to get him in the Down or Play Dead position and then physically roll him over. This technique may not work with dogs that find the loss of control frightening. Here is a step-by-step guide to teaching the dog behavior Roll Over Command.
"Down"
If your dog doesn't already know the down command, teach him from the sitting position. Give the command and gently push him down. Immediately reward him with praise and a treat.
"Play Dead"
Once your dog has mastered the down command, teach him Play Dead or Over. Get him in the down position and then gently turn him on his side while saying "over," "play dead" or "bang!" while pointing your finger like a gun (this form of Play Dead is great entertainment). As soon as he rolls onto his side, heap on the praise and offer a treat.
"Show Me Your Belly"
The next step is to have your dog roll over completely on his back. This trick is relatively easy to progress to from the Play Dead position because most dogs love to have their bellies rubbed. With your dog lying on his side, begin enthusiastically rubbing his tummy. As he lifts his leg to allow for more rubbing, gently turn him onto his back while saying "show me your tummy." Immediately reinforce with a reward. Over time, you can phase out the belly rub and just offer a treat.
"Roll Over"

Keep the training sessions short and remember that these sessions are opportunities for you to bond with your pet. If you and your furry friend are feeling irritable, quit the training and come back to it when you can both enjoy the time together.