I've installed a new head unit (Sony Xplod CDX-GT62IPW) and new speakers in the rear (Sony GT6935A)...All of that works, and sounds pretty good..but...

My question is: is there any way to remove the rear speaker grilles to put the new ones on? Or must I leave the stock grilles on? I'm aware that the seat belt housing is underneath and runs through the left side speaker grille, but I'm just not sure if there's any way around this???