Populating complex objects programmatically in C# (by Reflection or Roslyn)

Suppose I have the following classes

public class Course
{
    public int CourseID { get; set; }
    public string Credits { get; set; }
    public int DepartmentID { get; set; }
    public virtual Department Department { get; set; }
    public virtual ICollection<Department> Departments { get; set; }

}

public class Department
{
    public int DepartmentID { get; set; }
    public string Name { get; set; }
    public decimal Budget { get; set; }
    public DateTime StartDate { get; set; }
    public int? Administrator { get; set; }
}

How can I populate data to instances of Course type (all properties) programmatically?

Please do not suggest a specific library. I want to learn the technique by Reflection or Roslyn.