Cot to cot bed move

Anna • Baby #2 on board

Last night we changed the cot to the cot bed for our 2 year old. Obviously there was mayhem and he can open doors so he left his room and was running everywhere and wouldn't get in his bed. In the end he slept with us and I don't want to make this a habit. Any advice on how to help him sleep in his bed would be greatly appreciated