How do you change the gear box oil on a Peugeot 306 petrol?

To change the gearbox oil on a Peugeot 306 petrol, start by ensuring the vehicle is on a level surface and secure it with wheel chocks. Remove the drain plug from the gearbox and let the old oil drain completely into a container. Once drained, replace the drain plug and remove the fill plug on the side of the gearbox. Using a funnel, add the recommended gearbox oil until it reaches the fill level, then replace the fill plug securely.