Get parent component from child class

[I have two custom component classes (Class1 and Class2, Class1 has a Panel component that i am using to set and get other components to/from (label, textfield…), in my Parent class (Class1), i set the content of the panel to (Class2), i want to now from Class2, set the panel again to Class3 but how can i access the panel if it was declared in Class1?/b]