Well, it is not so difficult :
1. Download to a temporary directory.
2. Unzip to the same, or other temporary directory. Packages almost always contain 2 folders: Panel and Gauges. These will be unzipped to the temporary folder.
3. Copy everything from unzipped Panel folder into the aircrafts own panel folder, and overwrite anything there.
4. Copy everything from unzipped Gauges folder into the FS2002/Gauges folder.
You are ready.
