I have an extra clean bin ready to transfer them into. I simply pick up the egg crates and turn them upside down a few times for all the loose stuff to fall off. Then put the crates into the clean bin. With a paintbrush, I sweep all the stuff to the center of the bin, put a couple more egg crates in, wait about 10 mins. or so, by then most of the roaches have climbed on the crates. When you sweep the stuff onto the dust pan or whatever you use ( I use a small piece of sheet metal), the remaining roaches usually run away to the edges of the bin. You don't have to worry about getting every little thing. It's better to leave some frass and molts, as the babies eat it.