How do you change gearbox oil on xsara picasso 1.6 hdi?

To change the gearbox oil on a Citroën Xsara Picasso 1.6 HDi, start by ensuring the vehicle is on a level surface and securely lifted. Remove the drain plug from the gearbox and let the old oil drain completely. Replace the drain plug, then remove the fill plug and use a funnel to add the recommended type and amount of new gearbox oil. Finally, re-secure the fill plug and check for leaks before lowering the vehicle.