I'm sure you already did, but just to be sure, take the square black rubber plug thingy with a hose sticking out of it off the side of the oiler and fill the exposed hole with a bottle having a spout that will fit, the Scottoiler bottle with the pipe on it is perfect, (unsurprisingly
). Don't go too fast, if you do it sort of airlocks and spills oil around, (I may have done that myself before now
).
Unless it's already full, which might be why the oil spills out I suppose. But then it wouldn't be working, which I'm sure you would have spotted.