I've made the switch twice with no problem. I did it with my tuxedos because Oreo kicks the litter like he is digging to China. I scooped out the open box and dumped the contents into the new box sans cover. After a few day I put the cover on. I did the same thing with my Siamese. Now I have my sons cat. I am using my spare open box. What a mess. A new Boodaloo is on the way. Hope it works.