squeaky brakes dont necessarily mean they need replaced.
generally squeaking WHILE braking is a pad/rotor/shim/contaminate etc issue. they arent squeaking due to being worn. and usually a non issue, as far as safety is concerned.
squeaking all the time, while NOT braking is generally a sign of worn pads.
if you change pads, without doing something with the rotors, you are just begging for problems. whether it be squeaks, pulsation, pulling whatever.
atleast the rotors need buffed out, but preferably to be resurfaced, to give the new FLAT pads a nice parallel surface to bed against. and it also removes the old embedded friction material.