Don't be tempted to use metal objects! I made that mistake once and damaged a grill.
Tape rarely works for some reason.
I know it sounds silly, but swipe some of those Priority Mail tags from the post office. Place it on the grill and rotate counter clock-wise. They are less sticky (no residue) but work well.
Of course re-use it when you're done because it's not really legal unless you're planning on shipping something out As if they'd care...
I ended up just taking 2 toothpicks and putting them in the grille and it came off so easily lol... I feel stupid now for wasting all that time trying to get it off by hand.
Blew in there a little bit to get any possible debris out and the rattling seems to be gone for the moment... but then again, most of the time it will come back, heh.
Amazon gave me a return label so I can ship em' off I want to any time before the 24th when the 'return window' ends... but the thing is I can't get an exchange. Would have to get a full refund and buy them again from somewhere.