If for any reason you need to do a custom restore of your iDevice using iTunes, you can do so by first clicking on the device in the iTunes menu on the left. Make sure you hold down the ‘alt’ button before clicking ‘Restore’. By holding down ‘alt’ you are forcing iTunes to look for the restore file locally on your mac. If you don’t hold down ‘alt’ iTunes will restore your iDevice using Apple’s preset restore files.
Remember to hold down ‘alt’ button before and while clicking ‘Restore’ until menu pops up.