Search and Replace for WordPress Databases Script

Hi,

This is a question about instructions for using the “Search and Replace for WordPress Databases Script,” recommended at this link, under the section marked, “When Your Domain Name or URLs Change”.

The instructions say:

To use the script, you should install it in the root folder of your WordPress install

My question is, which WordPress install, the one you are moving FROM, or the one you are moving TO?

In my case, I am moving WordPress
FROM:
http://houston-websites.org/prototypes/WordPress/TransitionIn/

TO:
http://houston-data.com/DansDemos/WordPress/TransitionIn

As always, any assistance would be extremely much appreciated.

Thank you.