Talk to a counselor at your college. If you have an acceptable reason for having failed the class, such as medical emergencies preventing you from attending the semester, you may be able to remove the failing grade.
Petition the grade. Depending on your college, there will be different criteria for which you must qualify, in order to appeal the grade. While this method will not outright remove the grade from your transcript, it will no longer bring down your GPA, if successful.
Retake the failed class. If you were unable to attend due to financial difficulties, save up well in advance, to prevent the problem from happening again. Alternatively, seek free financial aid. If you were unable to pass the class due to difficulty understanding the material, take extra care to study hard. Ask classmates, or the professor to help you get a better understanding. If you complete the class with a higher grade, the transcript will reflect this higher grade.