Just a note, if the 4 screws of the knee panel are still with their cover caps, pry them loose VERY gently and use plastic tools, they get scratched very easily and are visible, so once ruined you will regret it.
Likewise, the screws need their proper size screwdriver to fully engage in the cross.
Once you remove the knee panel, the flimsiness of its mounting points will show in all its true glory. Go carefully over each plastic "pillar" where the screw passes through, in order to check for cracks or broken bits in the (flimsy) plastic. If there, pass through with some heavy duty glue like poxipol to save them from certain destruction.
When you put back together the panel, do not over tighten, lest accelerate the breaking process described above. Is enough the panel just not to rattle, it is not structural so does not need too much pressure by those pesky screws ....