battery-alternator

i have a 2002 saturn ls300 and today the battery light came, and it didn't turn off after a few seconds. so i drove home and the light stayed on the entire time. i looked in the manual and did some trouble shooting and the car beeped 4 times indication that the battery isn't charging. the battery is a acdelco 6 year battery that is only a year or 2 old, so i dont think it is the battery. i think it is the alternator. and i would like another opinion. and i would also like to know the easist way to remove the alternator.