Question Migrating Users to New site: Different Domain Name?

I was looking at www.kunena.org/docs/en/faq/migrate-the-f...-users-to-a-new-site and had a question before completing this step. I setup a new version of the site on another domain name for building purposes. I want to transfer the users, to test it out before applying the previous domain name to the test site. If I follow the steps listed above will this crash the Test Site because it has a different domain name?

I setup a new version of the site on another domain

Is the new version of the site a copy or a clean new Joomla installation?
A different domain name should not be a problem, otherwise it would not possible to create local a complete webpage and afterwards to move to a web server.
When the new version of your page is a clean new Joomla installation, it should work without extra settings.
But if it's a copy, you need to adjust the configuration.php and empty the cache (he can contain infos to the old domain).

It is a copy of an existing Joomla site with Kunena, all up to date and matching the versions of the new install.

When it's a copy, you don't need the steps of this wiki. You need this only, if you want to migrate an old forum to a new installed Joomla.
In your case, the users exists already. You can copy your complete web page one-to-one along with Kunena and your complete database to the new address.

1. Copy the complete Joomla web page to the new address
2. Import the complete database from your old installation
3. Open the configuration.php and adjust:
* database name
* database user
* database password
* path to the log folder
* path to the tmp folder
4. Empty the Joomla cache
That's all

The problem that I was running into was that, on the new site I used a new template, etc. so that I didn't have to take the forum and site offline while it was in production.

I wanted to just pull the users and forum data into the new version and then do a swap in WHM of the accounts which should only take about 15 minutes.

On the new site I need the keep the new look, design, template, and all associated files for the new site. I've done the 1 to 1 copy before, but in this case I just need the users and forum.

Both sites have the same versions of Joomla and Kunena, running. Since I want to keep the template design intact with the new blog articles, if I just follow the Wiki instructions, should that be sufficient?

Let's go over it again.
You have a new page with a new look
You need for this page the users and the forum from the live page
In this case you need all Joomla user tables and all Kunena tables from the live page
When this is done you have a Joomla installation with new style inclusive users and Kunena tables but not a forum
Install Kunena
Now you need the avatars and attachments from the live page
Copy the folders media/kunena/attachments and media/kunena/avatars to your new page
With these steps remain the new Joomla style and the Kunena style is default.

Gotcha. Here's the missing information. The original site, we'll call it 123456.com is still running. I built a new version of this site on domain name 456789.com. I updated 123456.com to the newest versions of Joomla and Kunena and then updated the new version of the site 456789.com to the same versions. I then did all of the graphic and aesthic work on the new site 456789.com and it's ready to go.

I have them both installed in WHM and on a previous site with similar circumstances, I updated a new version and then renamed the accounts in WHM and swapped them. From there, I changed the configuration files, etc. and it worked. The difference was that I didn't need to import data, I just built over a copy.

On this one, the database is empty, but all of the versions and extensions are the same and the same version. Now, I want to import the data to the new site 456789.com from the live version 123456.com, make sure all is working well and then I'll do the WHM account swap to switch 456789.com to 123456.com.

What do you think?

You want also migrate all Joomla articles? Your way could work (try it). You can import the database for tests even now. Depending on how long you need for testing, you can remove this tables afterwards and then import the up-to date tables when there are new articles on your live page.
But if you import the tables from the live site, you need to install the new Joomla template again, because the template for the new style is not listed in the live database. Maybe it needs also some other adjustments.