I have not tested this paint in FS9 yet so this installation will be off what I assume will work.
1. Move the sound and model.w folders into the main folder and overwrite,
2. You can choose either the default 737 panel (panel) or the POSKY modified panel (OPTIONAL POSKY PANEL). For panel, just move to the main POSKY SI ONE 737 folder and overwrite. For the OPTIONAL POSKY panel, you will also need to move the panel folder and overwrite. Then, you need to open the OPTIONAL POSKY panel folder and follow instructions.
