It is very easy to adjust your glasses at home.
Firstly you should determine what is wrong with the way you glasses rest on your nose.
Look in a mirror and check if they are too high or too low, or if one side is crooked or tilts too much to the left or to the right.
Hold the frame of the glasses steady.
Use you fingers to gently adjust the joint that the nose pads sit on, depending on how you should have, the glasses to sit on your face. Move the hinges slightly until you will find the desired position.
Put the glasses on your face to check them until you will get the desired fit.