In the real world, preferences files serve a very specific purpose, preserving persistent data between application sessions. Real preferences files range from short to long, simple to complex, direct to obscure. Some are easy to read, others are not. Some are simple to hack, others not so simple.
Always remember that preferences files are created for the convenience of the programmer rather than for you. If the application developer had really wanted you to change a preference, he or she would have encoded it into the preferences panel in the application itself. Hacking preferences files directly is the kingdom of the excitement seeker or control freak.
Fortunately, the practical realities of programming lend a hand. Most preferences keys use readable and sensible names, albeit for the convenience of the programmer. Such keys as
SelectedVoiceName give a clear idea of what the preference does and how to go about changing its value.
For the most part, manually modifying preferences files is simple. Following are the steps you need to take:
Quit the ...