Not much detail given here at all so:
You don't have to manually put your skins anywhere in lazer as there are no folders for it yet like there are in osu! stable. Marco is showing how to export specific skins so you can put them individually into lazer, although it will be more effecient to do the second method if you have a lot of skins. Biso's screenshot, by coincidence, shows the "Import Skins From Stable" button, that is what you are looking for. Don't press any export buttons like he said to do though.