brother, its simple, as you can see the locks in the first pic,
if you have large uncut nails, you can open with them 
or just take a simple screwdriver, and place a tissue of piece of cloth (for not to put scratches on dashboard)
put the screwdriver in any corner or side of the grill, and it comes upward, then grip it in ur fingers to pull upwards further and, here it is 