Remove the left and right side covers and the front cover first which is held in by 2 small sliver T10 torx screws
the black plastic top cover is held in place by hooks that run along the side of both edges, you need to push the black cover back (or forward i forget which way) a small amount, and then it should lift up and away from the case
https://support.hp.com/us-en/document/c01756922