If you want to adjust it yourself, You shall first observe if the your nose pads aren't centered properly. Check the eyeglasses frames if it sit too low down on your nose so as to help you know how should you adjust the nose pads. And then adjust the nose pads as your plan to make them sit in proper on your nose and let the eyeglasses frames fix the right place in front of your eyes.
Nose pads on glasses are the key for the way your glasses fix on your face. When your glasses sit crookedly or in an uncomfortable position, you need to adjust them. It is just a easy job, and you just need care and small movements.
Steps are as follows: Place a small towel around the lens to protect from damage. Use the pliers to grip the pad, and gently adjust it according to the actual condition until the fit is comfortable. Repeat with the other side. Be quite careful throughout the process, or you may damage the frame.