Yes you can take off the speaker grille. But you have to take off the "shelf" first. After which you have to cut off the pegs of the speaker grille. I can't really describe how it is attached to the "shelf" but it is not screwed on. Once you cut the pegs off, you cannot put the speaker grille back unless you screw them on using your own supplied screws.
It's very easy to do. I did it when I replaced my speaker grille with the JDM version.