Remove all the screws shown in the picture (see arrows).

Next, gently pry the upper part with a plastic tool along the edge(s), as shown in the pictures. Be careful and patient! When prying out the upper part, you need to hear it 'click' . Every 'click' indicates that at that place the upper part is released from the lower part.

For your information: It is the upper part that needs to be removed, not the lower part. The lower part keeps and holds the mainboard and other parts, as you will see in the next step.