Forum Moderators: not2easy
Go up to "Layer" and select "Add Layer Mask"
Mouse over the paint bucket tool and hold down the mouse button until you get a menu. Select "Gradient Tool". If you have never used it before the default gradient is probably ok. Otherwise make sure the gradient goes from black to white (or transparent).
With the gradient tool click and hold where you want the gradient to start and drag and release where you want the gradient to end.
Ctrl-Z and do it again until you get it right.
I hope this helps.