If you're wondering how to add your own ringtones to the LG Spyder II 840, you'll need to realize that this phone doesn't use standard MP3s for ringtones.
The phone uses QCP files. Which means that you'll need to convert your MP3 ringtones to QCP which turned out to be quite simple because OCP files are basically the same thing as WAV files. So all you need to do is convert your MP3 ringtone to WAV file and then change file extension to QCP. After doing this, you can now load to your phone via an microSDHC card. Just remember to place the files in the "my_audios" folder and not the "my_music" folder on your memory card. Also, you'll discover from the phone prompts that you'll need to copy or move the QCP files to the phone's memory before you can assign them as ringtones.
If you were planning on using a MIDI file, then you shouldn't need to convert the file. The phone will recognize MIDI files just fine.
If you need a program to edit/convert your MP3s into WAV, then I recommend using Audacity. It's free and it works and did I mention FREE.
Overall, the instructions in this post has been tested to work on an LG Spyder II 840 that is offered by Cellular South. Other cellphone service providers may have added special blocks or placed other limitations to keep you from adding your own ringtones, but you're more than welcome to try my method to see if it works on your phone.
Leave me a comment if you find out if this method works or not for you. It might be useful for others who are trolling the web for information about this issue.