1. You need have is world of warcraft.
2. Go to Start then select My Computer.
3. Go to c:.
4. Go to Program Files then scroll down to World of Warcraft.
5. Go to Data and then go to enGB.
6. scroll down until you see Realmlist open it with Notepad.
7. Then edit it with the realmlist you want and save it.
8. If you want to play on EU-realms put this:

9. If you want US-realms put this:

10. If you wanna play on private servers with a launcher follow these steps.
11. this is only if your WoW version is higher then patch 4.0.0
12. If you wanna check your wow patch go to wow-4.2.0.2552-enUS-tools-downloader in your WoW folder mine is now 4.2.02552 or 4.2.0.
13. Then go to a site of a private server with your WoW patch so you can play on the server
14. Then make an account on the site.
15. Next thing you do is look on the site after the realmlist then put it in your WoW realmlist.
16. Then go to downloads section of the site or look on the home page then you see you can download the launcher.
17. Download the launcher.
18. Now copy the launcher to your WoW folder.
19. Run it and you are on a private server.
20. This is what you do for private servers.

Hope this helped for you guys.