It is a easy to replace a power button for galaxy note.
You need to remove the midframe. You can follow [guide|16247|the guide] to do that.
Releasing the midframe, you will find the power button is fixed in the midframe by two clips.
Share with u the [http://www.witrigs.com/replacement-parts-power-button-for-samsung-galaxy-note-sgh-i717-white|original Samsung Galaxy Note power button].