How Can I Get Rid of Sculptra?

Sculptra is a collagen stimulator. The effects you see are not Sculptra but the "results" of the formation of collagen because of the Sculptra particles injected.
Your facial shape changes all the time. Aging will definitely make the lower face look more square and heavier in almost everyone. What you hate now may not be Sculptra-induced at all.
In any event, even if the Sculptra is the reason, your own collagen will break down in its natural course. There is no method of selectively removing collagen.
The purpose of Sculptra is to restore volume in areas of the face where volume loss normally occurs -- in the cheeks, temples and some areas of the lower face.
What you after with any injected product is a balance of proportion and of contour. Sculptra is very much dependent upon injector technique. In the U.S. only certain physicians are allowed to use Sculptra and there is a training requirement in place.
Because "waiting" is not something that you will appreciate, you might consider speaking to a good cosmetic dermatologist who may be able to provide some temporary contouring with a hyaluronic acid to bring more emphasis to your cheek bones.
Again, the key is proportional balance.

I would say it would be pretty impossible to remove the Sculptra, unless you have isolated bumps that are bothering you. This material is injected like a slurry under the skin and injected all over the place, that it wold be difficult to remove.  It will run its course, but it will take a year or two.