At first, you may have to make a gradual switch, but as your dog gets used to the process and his gut becomes healthier, you won’t have to anymore. I used to have to take a month to transition with one of my dogs, now I just switch.
There is no one way to do a rotational diet. Some people switch bag to bag, some weekly, and some, like me, every meal. I have multiple dogs and go through a bag fairly quickly so I started having four bags open at once and as one gets empty I rotate in something else. I also feed some raw and change that every day too.
