Not sure what the proper way to integrate a 2 year old and a 4 year old who sleep in separate rooms to bunk beds. All I can do is give the advice on what NOT to do.
1. Besides measuring if the beds will fit, keep in mind what is on the wall and the floors as well. This way you will not get your new bunk beds installed and say, for example, now be turning on and off the light with a chopstick.
2. Transition is a slow process. Perhaps in hindsight I should have transitioned my 2 year old, Ben, from a crib to a toddler bed, then a toddler bed to a real bed. Because now as it stands he thinks this new arrangement is a big sleep over party and is keeping everyone up. Of course, I have no where else to put him…
3. Wednesday is not the best day to have your beds delivered. The best day to have your bunk beds delivered is a Friday. It’s already hard enough to get the used to the new sleeping arrangement. Don’t add a ‘school night’ bed time to the stress of it.
4. If both your kids wake you up all night, don’t assume throwing them in the same room will end your frequent night waking. They are of no comfort to each other. And when I finally got them both in the same bed, Ben woke up and tried to wake up Jack as well!

The New Bunk Beds!