As you already know, the iPhone is very picky when it comes to customizing ringtones and SMS. Changing them is easier than it seems.
Before you start applying the instructions, make sure you have the tones you want to change to mp3 format.
Step 1
converted .mp3 files to .aiff format using an audio converter then change the extension of the .aiff files to .caf.
Step 2
Connect to your phone using ifunbox and navigate to System>Library>Audio>UISounds where you have the tones for SMS. Before changing anything, save the file you want to replace.
Step 3
Look in that directory for the files named sms-received1-6.caf. My recommendation is to do it as follows, as I told you above, it is good to save the file you want to replace, so save the sms-received1.caf file in your computer and then rename the tone you want to replace put sms-received1.caf in the phone and copy it over the one there by selecting overwrite when you are asked.
Step 4
Navigate to System>Sounds>New Text Message and select the first tone. You will notice that the name of the tones will not change, but when you click on the first one, you will hear the song fragment you chose to be changed.
If you encounter other problems that are not covered by this tutorial, please ask me using the support page located here.
