After having removed the keyboard, you will see the ribbon cable of the touch pad cable that needs to be removed (it is located to the left of the ribbon cable holder of the keyboard).

Gently unlock it by lifting the holder (black part) with a plastic tool. The ribbon cable has a lug which makes it easy to pull it out of the holder after the holder is lifted.

For your information: This blue ribbon cable needs to be removed before - in the next step - the upper part of the PC is removed.