Changing LSD gear oil on 240SX?

[sk8kei]

if I need to change the gear oil inside the diff, do I have to take the whole diff out? I know that's a drain plug close to the bottom, but how can I fill in a new gear oil into the diff(which I don't have to take out the diff out) I notice that it has a small hole on the top of the diff, but how can I drink the oil in from there?

[GRiDRaceTech]

I don't recommend drinking the diff fluid.

You pull the bottom plug and let it all run out. Then, you fill it up from the side (with a squeeze bottle or a suction pump) until the fluid is level with the hole. Close 'er up and you're set.