Once all the 6 screws and 2 ribbons are removed, the battery should come free of the display assembly very easily.

With one hand on each side of the tablet simply turn the device on edge with one hand and tilt it over until the battery falls into your other hand.

If for some reason the battery does not come out, double check to ensure you have removed and unattached all of the 6 screws and 2 ribbon cables.