Upgrading to 1.9 from 1.8.3

[Dualtha]

Hi guys,

We am currently using TL 1.8.3 in production. We have the database backup on a weekly basis and have JIRA integration as some customizations such as extra test status included for the results\ reports.
All is working fine. However, we now want to try and integrate TL with our automated test suites using Hudson api. What we are wondering is can we simply take a copy of the current testlink directory in production and put in on a test server, import the backed up database then run the upgrade for 1.91?
I want to fully test this before touching the production machine.
When Upgrading to 1.9.1 I assume we use the automatic upgrade htpp:\\<SRV><TL1.9.1_DIR>install/index.php?
After I complete this do I remove the old testlink directory and just copy over my customized files?

Any information is appreciated.