How to remove angular 4 child component when changed the value from parent component

Hi Team

I have passed the array value from parent component to child component. the first time is working fine and display the form with form controls in child component.

When click the button from parent and passed the value to child component , the new form and form controls is working fine, but the old form with controls is still exist instead of removal.

Please help me how to remove existing form with controls from child component.

Thanks
Shugan