You can reassign owners to opportunities by using the Change Opportunity Owner found under System Information at the bottom of the opportunity. This is needed if you are handing off opportunities to a different development staff member or if you need to delete an opportunity someone else created. Only do this after you have confirmed the change needs to be made.
Click on the Change hyperlink
Type in the new owner's name. Click Send Email if you need to notify the new owner. If you are reassigning the opportunity to yourself then you do not need to click this box. Save the changes.