sound daft but how do i change the pannel filter over

looking at the box there are 2 screws at the back and clips on the front

do they unclip or have i got to remove the screws?

havent realy got a clue where to start

If a standard box, undo the screws and then you can remove the cover by pushing the cover down a bit and wiggle the cover towards the windscreen to release it from under the clips.