Add a little sauce/meat mixture to the bottom of the pan, then cut the lasagna noodles to fit the 9″ square pan. It should take 2 noodles, cut to size, to cover the bottom. Then layer half the meat/sauce mixture, half the ricotta, half the mozzarella, then half the cheddar. Repeat. The pan will prolly be extra full, so make sure you put the pan on a baking sheet.