Ask Marc for a copy of his manual - covers all aspects of growing.
From what I have read so far, osmotic shock is a reasonable good way of extracting oil. I have not got to trying it yet but will soon.
I will be partially dewatering the harvested cells by either centrifuge or just drip drying, and then dropping it all straight into a tank of distilled water. Hopefully the oil will float to the surface and the dead cells to the bottom, making getting the oil easy.
Let us know how you do.
Slippery
Small steps taken one at a time.