look above the ns inner cv joint
there is a 17mm female hex hole this is the fill up plug
its easier to fill from inside the wheel arch through the steering rack arm opening, use a 1l gear box oil with the pull out plastic spout and use a piece of hose that is about 12" long and fits over the spout and in the hole where the plug was
think the hose size i used was 14mm inner diameter, pushed on to the spout nicely