From the information you provided, I am not sure exactly why you want them removed. A picture showing the scars you mentioned and the contour of your face would be helpful.
To answer your question in a general context, the contour threads can be removed. Usually, this is done by making an incision along the same point where the threads were put in, just above the sideburn area. It can be a little difficult sometimes finding the threads, especially if they have migrated from their original point.
Once they are located, they can be pulled out with relatively little tension. Potential problems are that the threads may be difficult to find or the threads may break, leaving some portion of them behind that will have to be retrieved later. Creating new scars from this removal process would be unlikely.