adjusting brake light switch

I have a 2006 Chevy Malibu Maxx. I realized recently that the brake lights don't come on under normal braking, but if I press the pedal harder they eventually come in. It's consistent at which point they come on, so I assume I need to adjust the switch under the brake pedal. Can someone please give me some basic info on how to do this? Thanks.

There a or two sensor on the brake pedal push both up so that they can be closer to the pedal (you see the action when you press the pedal) open drive side door get under the brake pedal without the brake pedal depressed you should see the sensor press the brake pedal with your hand and check how much does the sensors have to be pull up