In order to transfer classes from one monitor to another we will go to:

Planning → Instructors → Instructors List

In this window we will find the list of all the monitors we have, we will click on the button   of the monitor that we want to transfer one class to another.

Once inside the tab of the monitor we will go to the option of "Classes calendar" in the menu on the left and "Schedule" in the window on the right. Where we will leave all the classes that will give this monitor, we will click on the button of the class that we want to transfer.

When we are inside the class in the "General" option of the menu on the left, we will see the options of the class, the students enrolled, the date and the hour etc. We can also see a drop down with all the monitors, the monitor will be marked, but if we want to change it, we just have to click on the drop down and click on another monitor in the list (as shown in the image provided), click on the Save button and we will have made the change.