Just got this used phone for school.how to change the ringtone It's a very annoying one now.

Usually this is done one of two ways
if the phone has a menu button
press it once then use the arrow keys until you see "ring" or "ring tone" in the display
then use the arrow keys again and you should hear different ring tones. when you find the one you like press the menu button to lock it in

if the phone has a program button and no menu button
keep pressing the program button until you see "ring tone" in the display.then use the arrow keys until you hear the ring tone you like. then press the program button several times until you exit the programming mode.

you can follow the above steps to set the ringer volume also