GSX Stair Replacement: No FW2458PE + Universal CDS 2438 Stairs

This add-on modifies GSX by removing the FW2458PE stair type and enabling the use of CDS 2438 stairs for all B737 and A320 variants. The existing stair types with a cabin remain unaffected and continue to function with all aircraft. Detailed installation instructions are provided, highlighting the need to replace certain files after GSX updates.