Use [http://www.acehardware.com/product/index.jsp?productId=20751526|ABS cement] and [http://www.amazon.com/For-Pro-Acetone-Remover-Fluid/dp/B0006PS3KI/ref=sr_1_2?ie=UTF8&qid=1414218737&sr=8-2&keywords=acetone|acetone] to fuse the plastic together, as per [http://faq.ninja250.org/wiki/Plastics_repair_with_ABS_cement|this guide]. This is the kind of thing autobody guys do all the time. Also, bondo.