Visit your college's website and access their student portal. Many colleges have fully digitized their records and you can access information on your grades for specific classes even after you are no longer enrolled.
Request your college transcripts either online, over the phone, or in writing. If a college allows for online requests, the process will be detailed on their website. Otherwise the website will provide an address and phone number. Many colleges print not only the final grades for each class but the exam grades for each class as well on the transcripts.
Contact the department which administered the class directly with your phone. Their number will be listed on the college website and in their directory. Often, the department will maintain detailed paper records of student performance for future reference.
Contact the professor of the class in question directly with your phone or through e-mail. Instructors will keep records for several years to analyze and promote consistency and fairness in their grading procedures.