To ensure a smooth transition to fresh food, feed a mix of the labeled transition portions with their current diet, then serve full portions afterwards. If you did not receive transition portions (and did not opt out of them), split the Nom Nom portions in half for the first week and combine with their current diet and gradually work your way up to full portions.
If you ever need to double-check, you can always find your pup's specific feeding instructions in your account's Quick Start Guide located under the Account Actions section of your Plan page. After the initial transition, your pup should be able to rotate between all Nom Nom recipes without a hitch!