Open the library (press f11)
- Find the background sound file (the file name varies in different templates).
- Delete the file (however be sure to write down the file name).
- Import another audio file (e.g. MP3 file).
- Rename the new file to the former one.

It is usually far easier to locate the content by opening the library window
(F11 or Window Library) and selecting each item until you find the content
needed, double click on the icon associated to the left and Flash will kindly
bring up the element for you to edit.

Simply select the text that you wish to change using the pointer tool and
double click on the text area in order to change the text. Here you can alter
the text size and font as well using the properties window (Ctrl+F3). We also highly recommend the find and replace function.