To Change a students grade level and add new ones you need to go to:

1. Core > Users > Edit User Profile Data
2. Look up the Student 
3. Go into Student Enrollment under system information
4. Here you can edit the grade for each year. Note: If the Student has a Contract associated with that School Year, you will get a warning message as shown:
User-added image
5. You can also add another year by selecting enroll in school and filling out those dropdowns