If you stretch your lobe past an inch or so, or you tear it, and then decide that you'd like to go "back to normal," surgical intervention will be required. As with all cosmetic surgery, a general rule is the more you spend the better a job you'll get.
There are some piercers willing to do this procedure for clients, but realistically this is a job for a surgeon. It should also be noted that done in a non-surgical environment there may be bleeding risks that can not be adequately handled.
After the procedure a small linear scar will usually be left. This scar will reduce over several months, and CO2 laser resurfacing can all but eliminate any scar.
The reconstructed earlobe can be re-pierced and even stretched again if desired.