1. Connect the phone to the computer and drag the ringtone file from your computer to the phone as follows: Use your flash card, USB cable, or bluetooth to navigate to your DCIM directory on the phone. Inside that folder is a folder named 100xxxx. This is where the .3g2 video file (your ringtone) should go. If the ringtone is not in this directory then you won't be able to find it when you're looking for it from the phone. I did not illustrate this part because I'm assuming everyone has some familiarity with using standard Windows windows.
2. Use Windows Explorer to drag the file from your computer to your phone. If you have several ringtones, you can move them all at once.
3. End your session on the phone and go back to your startup screen. At this point it does not matter whether you disconnect the wire or not. If you installed directly on your micro flash chip, just plug your chip back into the phone. Once you get the hang of this, it will take you a little less time than the QuickTime Pro conversion.