Lay on your back on the floor on mat (or whatever you have), with no pillow. Palms up, raise your head, then chin down and lay your head back down. Close eyes.
Now inhale 1,2,3,4, then exhale 1,2,3,4,5,6. Do this 3 times.
Now starting with feet, feel them relax. Do nothing else until your feet are relaxed.
Now your legs. Feel all the muscles in your legs relax. They will start to feel heavy, like sinking into the floor.
Now the hips and buttocks. Totally relax. Go no further until they are doing that sinking feeling.
Now the chest. And back. We have many muscles. Relax chest and back.
Now the neck. This is reason for the chin down thing. It relaxes the back of the neck. Really take your time with this.
Now the head and face. As you relax the face, your jaw will open slightly. You are relaxed. Take your time.
Now in your mind, think of sounding "One, one, one" with each breath.
You are in total relaxation. Stay as long as you wish. When you are done, open eyes and get up slowly. You should feel rested, even as much as a nap gives you.