From the shown picture on the site World of Warcraft we should cut the next fragment and place it the same way it is shown below.

Keeping pressed the Alt button, make a click between the picture’s fragment’s layer and the inside zone.

Take from the same site the logotype World of Warcraft and place it like it is shown next image.

Having this tool represent the lowest layer of the buttons’ menu.

Blending Options-Gradient Overlay

Gradient’s parameters:

Blending Options-Stroke

Gradient’s parameters: