How do re-sink an Xbox 360 wireless controller

Find the sync button on the Xbox 360, this will be a small button. On the Xbox 260 slim, it will be above the USB section.
Find the sync button on your controller, this is located at the top of the controller.

After when you have found all these, just press the xbox 360 sync button and your wireless controller button (you do not need to press them at the same time).