Help - What does this mean? "Export the full DB and inject into new install."

Following the advice https://modx.com/blog/2015/09/21/migrating-your-modx-site/

And then I get to this instruction:

"Export the full DB and inject into new install."

What does that even mean? Should my new install have a fresh database which I then "inject" my old database into? How do I even do this?!

Is there anywhere better to get help or is this it?! Even the "Buy Emergency Support" link doesnt work.

I installed with a fresh database ( as was the only option ). Front end showed splash screen, back end showed an error "Uncaught exception 'Exception' with message 'DateTime::__construct(): Failed to parse time string (CST6CDT) at position 3 (6): U.... yadda yadda.

Battering on ahead in spite of that message and just guessing at what that instruction meant in the previous post, I tried dropping the database made on install and imported the old database instead. Still the same errors etc.

Just no idea how to approach this at all. Nothing seems to work properly and I don't know why so where do I even begin to make the right choices on how to debug this or start over (again)? Charged client for 1/2 a day to move servers and increase version and I'm still not able to make it work 2 days later! An incredibly frustrating experience with modx.

try to find the date_timezone System Setting in the modx_system_settings table in the database and set it to one of the values here: http://php.net/manual/en/timezones.php That should fix the error

Manually delete all files in the core/cache directory after fixing the DB setting before trying to log in.

"Export the full DB and inject into new install."

What does that even mean?

In the old site, select the database in PhpMyAdmin and use the Export tab to export it to a SQL file. Click on "Custom" and select the "ADD DROP TABLE ... " option. Then it won't matter what's in the new DB. Leave everything else at its default.

Create the new DB and use PhpMyAdmin to Import the SQL file.
As Paulp says, manually delete all files in the core/cache directory before logging in. You may also have to clear your browser cache and cookies.