Part One: Preparation
1) First of all, you should turn your board offline to prevent users from adding content during the transfer.
2) You should ensure that your new server meets the requirements for IP.Board.The requirements, along with a script which can check those requirements can be found here.
http://www.invisionpower.com/support/faqs3) You should check what the MySQL version is for your current server, and what it is for your new server - your host will be able to provide this information for you if you are unsure what versions you have.
If the version for the new server is newer than the old server, then you should be okay. If it is older, you will need to perform a compatibility backup when you get to step 4.
Part Two: Downloading Data
4) Backup your database using your preferred method. IPS recommends using phpMyAdmin which is a popular database management tool available on many hosts. If you have a particularly small forum, there is a backup tool in your Admin CP under the "Support" tab - but this may not work with larger databases. If you are in any doubt talk to your host.
5) Using FTP, download all of the files from your current server, preserving the directory structure.
Part Three: Uploading Data
6) Create a blank database on your new server, note the username, password and database name.
7) Upload and import your MySQL using your preferred method.
You can use a tool such as bigdump to import the database.
8) Upload all of the files you downloaded in step 5 to your new server, preserving the directory structure.
Part Four: Final Steps
9) If you are keeping the same URL, transfer your domain to the new server. Your new host and domain name provider will be able to provide assistance with this. Note that it will likely take up to 24 hours for the domain name to fully propagate.
10) On the new server, open the conf_global.php and fill in your new database details as created in step 6. The particular variables you need to edit are: $INFO['sql_database']$INFO['sql_user']$INFO['sql_pass']$INFO['sql_host']$INFO['board_url'] 11) In your Admin CP, go to the "Support" tab and select "Permissions Checker" - fix any problems it reports.
12) In your Admin CP, go to the "System" tab and select "System Settings" - go to the "General Configuration" group and change the "Upload path" and "Upload URL" as required.
If you use IP.Blog, IP.Gallery, IP.Downloads, IP.Content or IP.Nexus - you should also go into their respective settings and change any relevant paths.
13) In your Admin CP, go to the "System" tab and select "Cache Management" - press the "Recache All" button.
14) In your Admin CP, go to the "Look & Feel" tab and select "Template Tools" - press the "Recache Skin Sets" button.
15) Check you can access your board, and if so, turn it back online.