How do you fill up the 4 SPEED Automatic gearbox oil on a Peugeot 407?

To fill the 4-speed automatic gearbox oil on a Peugeot 407, first ensure the vehicle is on a level surface and the engine is running at idle. Locate the transmission dipstick or filler plug, usually found on the top or side of the transmission. Remove the dipstick or filler plug and use a funnel to add the appropriate automatic Transmission Fluid (ATF) until it reaches the correct level, as indicated on the dipstick or by the overflow from the filler plug. Finally, replace the dipstick or plug securely and check for leaks.