1.5litres of your chosen fluid which means you have to buy 2 x 1 litre bottles. Easy enough to drain and refill, take the filler plug out first to make sure you can get it out before draining the old fluid. The filler and drain plugs are tapered threaded and do not have sealing washers. I use a length of plastic tube attached to the new oil bottle and route it down through the engine bay into the filler plug hole and add new oil till it starts to overflow when its full.
Same for rear Diff fluid change but these plugs do have alloy washers which will probably have turned to lace if they are original, replaced mine with copper sealing washers when I did mine.