If the original piercing was done with a gun (for instance at the mall) you will want to wait until it has healed completely, which takes from between six to eight weeks. Then you can go to a professional piercer and have them stretched. You probably won't be able to go far on your first stretching, most piercers won't stretch more than a gauge or two. You'll need to let that heal before stretching again. Piercers do have the ability to pierce your ears right away at a larger gauge, so you wouldn't have to go through as much stretching. As to whether your ears will heal back, it depends on what you mean by small. Most of the time if you haven't had the large gauge plugs in for very long and haven't put weight into them, the holes will heal up again.