On the DeliciousBrains.com site they've posted the latest installment for their "Hosting WordPress Yourself" series (part 12) showing how to move your WordPress installation over to a new server.
In part 11 of Hosting WordPress Yourself I demonstrated how to update a server’s packages (including PHP). However, I didn’t show how to upgrade the server itself, because it’s not something I recommend.
[...] In this article, I’m going to walk you through the steps required to migrate an existing WordPress site to a new server. These are the same steps that I took just a few months ago to migrate the Delicious Brains site to a new server with little to no downtime.
The rest of the article is broken up into several different sections, each with descriptions and commands/code you'll need:
- Securely Copying Files
- File Migration
- Nginx Configuration
- HTTPS Certificates
- Spoof DNS
- Database Import
They also include hints on migrating with minimum downtime and things to look out for when you "flip the switch".