Oh, it's easy!
Wash, dry, and tear up the kale.
Put a little olive oil on it - maybe a couple teaspoons for a bunch, and rub it in. Do it in a ziplock if you don't want an olive oil manicure.
Season it up any way you like - sea salt & rosemary; salt, pepper & garlic powder; salt, cayenne & lime zest; salt, curry powder & cumin - go nuts!
Spread on a cookie sheet and cook at 300 degrees for 35-40 minutes, til it's crisp.