brake pads

If you are going to do this type of job, you need a copy of the manufacturer's service manual. It will have pages of instructions with line drawings, torque specs, and a list of special tools, if needed. You can also buy a subscription for just your car for a year online, but I prefer paper. Those sites include AllData and Mitchell-On-Demand. Those are what most independent repair shops subscribe to.

Once you have the service manual, come back here before you start tearing things apart. There is way more to a professional brake job than simply hanging a few new parts on the car. I will share some things to do to prevent causing squeals and other noises, and things you must avoid.

Be sure the car is supported solidly on jack stands, and you must use a click-type torque wrench when tightening the lug nuts.

do i have to press any type of button before i jack the car up?

You shouldn't. Your car's owner's manual will have specific instructions. If you have air ride, there may be a few things that you should do prior to jacking the car up.

I do not have a manual. what are the few things i should do prior to jacking the car up if the car have air ride?

You are supposed to turn the system off if you are going to raise it by the frame. That will let the rear axle drop making it look like the rear is riding too high. On some models that will not cause a problem as long as you do not turn on the ignition switch. On other models opening a door can activate the system or they are active all the time. In response to appearing to be too high, the system will exhaust the air from the rear air springs. The problem comes in when you let the car down onto the ground. The deflated bags can get pinched between suspension parts and be cut.

Most commonly the switch is located inside the trunk near the right inner wheel well.