Step 1.
Download and install the Sony Ericsson Digital Rights Management Packager
Windows :
link
Mac:
link
Step 2.
Select a mp3 you would like to protect (use as a ringtone).
Step 3.
Run DRM Packager
Start->Programs-> Sony Ericsson-> DRM Packager-> DRM Packager
Go to File, add files and select the mp3 you would like to use.
Step 4. (Configuration)
Go to Options -> Configuration -> and select combined delivery and also uncheck
“ Place rights in separate folder” and click the little box with the … on it and place where you want them to go (ex. My Documents/My Music folder) click OK
A window will pop up saying “Before proceeding with the combined delivery…. “
Click OK. Use the following info to fill in the blanks.
Content ID: myCellPhone @ Blah.com
Enable right = checked
Check Start time checked and date set to (which ever today’s date is)
Check End time checked and date set to (which ever today’s date is but year 2015)
click OK
Step 5 Creating the dm file(s)
Click on your MP3 file to highlight it
Click on Create DRM content
Now you can send this file to your device , you will be able to set this mp3 as a ringtone.