Start up FlexBuilder / FlashBuilder.
From the Help menu, select ‘Software Updates > Find and Install…’
Select ‘Search for new features to install’ and click ‘Next >’
Make sure only ‘Flex Formatter’ is selected in the ‘Sites to search’ list, and click ‘Finish’
Follow the prompts to install Flex Formatter, and restart the IDE
Once you’ve restarted, you should see the Flex Formatter bar with buttons to ASDoc, format, and rearrange your code. You should also have a ‘Flex Formatting’ entry in preferences.