What model of laptop is it?
As said above it'll usually just be on the underside of the laptop from an easy access hatch. When it's like this I find it easier to replace laptop memory than desktop, click out, click in...
You could find both under the keyboard or one on the bottom and one under the keyboard. Not the end of the world though, depends how easy the keyboard comes off...
Unless you're comfortable taking laptops apart, I'd agree with the above to leave it should you have to rake under the keyboard...