Try making a sleep schedule for yourself and strive to adhere to it.
Get yourself an alarm clock and set an alarm to eliminate oversleeping.
Try to expose yourself to natural bright lights. Ensure that your room is also filled with bright light through the day as it helps deal with symptoms of oversleeping.
Certain medical prescriptions can alter your sleep cycle and result in oversleeping. In such a case, consult with your doctor for an alternative treatment.
If none of these remedies work, visit a doctor to discuss your issues and test for any underlying problems.