How to change Sever?

How to change sever??? My friends are playing on sever 10 and 6 and I'm at 15. It seems I can't add them as friends as we are on different sever??/ So how to change sever or what are my alternatives?

P.S I'm new and this is my new post. Hi all

you cant change servers. youre stuck where you are

You can always try making new accounts with new devices but it's not sure thing.

server 10 and 6 are probably closed servers. no number of devices would make a difference

Thank for your help guys. It's very unfortunate that I can't change severs and play with my friend.... but I'll live with it.