How do you change the hydraulic oil Hydractic 3 citroen c5 2001 model?

To change the hydraulic oil in a 2001 Citroën C5 with Hydractive 3 suspension, first, ensure the vehicle is on a level surface and the engine is off. Locate the hydraulic fluid reservoir, typically found near the front of the engine bay, and remove the cap. Use a fluid extractor or pump to remove the old oil from the reservoir, then refill it with the appropriate hydraulic fluid, ensuring you do not overfill. Finally, start the engine and cycle the suspension to allow the new fluid to circulate, checking for any leaks before closing the reservoir.