You can move your students from one class to another through the teacher dashboard. This is done from the roster tab inside of one of your classes.
1. Selecting the student(s) that you want to move.
2. From the bulk options dropdown in the upper left, select the move option.
3. Click the apply button (this will prompt you to select which class you'd like to move the students to).
4. Select the class to move the students to.
5. Click the OK button.
6. Save your changes to have your student moved over into your other class.