step by step:
from the iTunes menu select edit, preferences, click the import settings in the middle of the screen, select MP3 encoder import using drop down list, under setting select custom which will open a new window, press default to ensure everything is set then select 256kb as the bitrate to retain the same quality as the 256kb AAC file, press OK to close all the windows back to iTunes.
Now right-click on an iTunes AAC file and select create MP3 version. You probably want to listen to the first few songs until you are comfortable with the process and happy with the results. I then delete the AAC files, but you may want to retain them.
Scott
from the iTunes menu select edit, preferences, click the import settings in the middle of the screen, select MP3 encoder import using drop down list, under setting select custom which will open a new window, press default to ensure everything is set then select 256kb as the bitrate to retain the same quality as the 256kb AAC file, press OK to close all the windows back to iTunes.
Now right-click on an iTunes AAC file and select create MP3 version. You probably want to listen to the first few songs until you are comfortable with the process and happy with the results. I then delete the AAC files, but you may want to retain them.
Scott