This guide leaves out some critical information:

In step 1 there are two additional screws under the removable panel at the bottom of the picture.

In step 2 it should be noted that the keyboard and trackpad connectors have tiny clamps that should be dealt with carefully. If lost your Duo will no longer function unless you can somehow find replacements.

In step 3 there are four additional screws not mentioned that must be removed before the top panel can be removed. I nearly damaged my Duo irreparably by first unsnapping the sides with a flat spudger and then attempting to lift the panel off. Once the four unmentioned screws are removed the panel comes off easily.

Following this guide to the letter will result in either confusion or damage to your Duo.