Thanks again guys for the explanations and diagrams, which is most helpful

Just a couple of questions.

Is it really necessary to return the oil? Is there that much oil lost that I really should return it, especially if I am driving the car often ??

Also, in the picture of the tank below, I guess its the smaller of the two bottom pipes that is the oil return? The one that is labelled to go to the turbo side of the block with adapter?

The adapter is the ebay item ?