There are times when you need to move WordPress around within your server, and times when you need to move WordPress from one server to another. You don’t need to reinstall. WordPress is flexible enough to handle all of these situations.
in order to transfer WordPress to new server you need to follow these steps:
1. Backup the database from the old site and import it to the new site. Pay attention to database names.
2. Change your wp-config.PHP in the old site to point to the database on the new site. Your old site will now run using database based on the new site and once you change the names servers new site will have the up to date database. (You may want to check with your new hosting if they allow outside database access first. If not, you can skip this step and transfer the database at the end, when the nameserver change propagated)
3. Backup your entire WordPress installation from the old site (this will include all your uploads, themes, plugins)
4. Unpack your WordPress installation to the new site
5. Change wp-config.PHP on the new site with new database details
6. Change the nameservers to point to the new site
7. That’s all now you only need to wait