I've used Wavepad to make my tones. Found it in a google search. It is pretty simple to use. There are other options. What u have to is google "audio editors" and choose the program that offers what u need. Hope this helps! PM me if not.
To make your own ringtone, go to the help section, then select Ringtone Maker, from there you will go through a step by step guide on how to make a ringtone.
If you are trying to upload a tone you already have from the PC select Upload Tone on the control panel. To upload a tone from your phone, send it to your personal upload email address located under the my account section of your page.