Easy peasy , no cutting of the kit involved . All you need is some thin plastic strip , xacto and sanding stick .
1, plastic strip ( width eyeballed
) 2. sand corners roundish , 3, bend and cut to size - test fit , cut again and glue . I usually just glue right over the cast cover . You can paint it black and rub it with HB pencil lead to give it a bit of a glass block reflection look . The covers operated independently ,so one open full , other open half or even closed . An easy visual up grade for little effort