go to http://wiki.howardforums.com/index.php/Software and get a p2k app
go to http://www.xlr8.us/hofo/map.txt and find the seem you need
either disable the tone or find out which file is the tone, back it up to your pc in case anything goes wrong, and make a file of similar size containing no sound and replace the one on your phone with that empty sound file ...done!
You can't just delete the tone file...you may have to change the attributes to be able to edit it and put them back afterwards (it may be read only).

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