How to change the screen position of an UI element by code?

I have tried to access the, pos x and pos y, RectTransform properties but without success.
In my scene I have a minimap in my canvas and I need to change its position in runtime by code,
Is there any way?
Thanks in advance

Solved.
You have to use:
GetComponent(RectTransform).anchoredPosition.x
GetComponent(RectTransform).anchoredPosition.y