VerticalLayout scroll to top

I have a Label inside a VerticalLayout, when the Label is long it shows the scrollbars. Then I can scroll the label to the bottom of the text. After that I change the Label to another value, but the scroll position remain unchanged (to bottom); how can I set scroll position to top after Label text change?
Thank you for your support

Can you provide code snippet, it will be much easier to understand what is your actual problem.
Thank you.