How To Get Kitten To Sleep Through The Night?

I have a 9 year old, male cat. He is very playful and mischievous , but very affectionate . I am hoping that he will get on with the kitten that my daughter just got him. She has had him since she was 3 weeks old, so she is now 15 months old. My question is how do you get your cats to sleep through the night? The kitten has been sleeping in her room for about 5 hours at a time and waking me up every 2-3 hours because of his scratching at the door wanting to come out and play or eat something (he loves tuna). He doesn’t seem like he will be able to cope with this kind of schedule all through out the day. I know they are still learning their own patterns but it seems like when we go away for weekends/days off etc., things don’t work out too well! Does anyone else have any experience or advice on getting them used to each other? Thanks 🙂