It's a motherwort. :o) I have a feeling that borage seed oil is extracted maybe by steam distillation... or as I read on Google, cold pressing. You could probably grind up the seeds and soak them in oil, it may not be as strong, but might have some of the aspects.

It's probably not a good idea to try to make your own borage seed oil, as it would contain potentially toxic alkaloids:

"Borage oil has been shown to contain small amounts of such pyrrolizidine alkaloids (PAs) as lycopsamine, amabiline, and thesinine. Some pyrrolizidine alkaloids, particularly unsaturated ones, may be toxic to the liver even in small amounts. Some herbalists stress that use of borage oil should be avoided unless the preparations are certified to be free of these potentially harmful, unsaturated pyrrolizidine alkaloids."

Here is a link that might be useful: Borage seed oil

Thanks for the responses :)