Allow removal of optional image

I allow my user to add an optional picture at will. Now later maybe she wants to remove it again. Does Qt offer any best practice for that?

From other programs I know a little X symbol in the top right corner. Not sure how to accomplish that easily, does Qt offer it at all? Does everybody program this functionality by themselves?

A right-click menu would be quicker, or pressing the delete key on keyboard. However both alternatives would be invisible at first and hard to find for the unenlightened.

How would you solve that?