Trouble removing pick guard on my strat

The little oval-shaped plastic knob covering the end of the pickup switch on my strat doesn't seem to want to come off (I'm trying to replace my pick guard). I guess I could just use some bigger pliers and pull really hard, but I'm afraid I'll break or damage it. I realize that replacement knobs are cheap, but there's bound to be some trick for getting those things off without breaking them, isn't there? I have no trouble at all getting the tone and volume knobs off.

Thanks in advance!