Exit Intent Pop Up Script and Wordress

1) Exit Intent Pop Up Script

2) http://dynamicdrive.com/dynamicindex...opup/index.htm

3) I'm trying to add this script to a WP Page created with Instabuilder Page Builder.
Adding the head code and body code is no problem but I can't figure out how to
or where to upload the ddexitpop.js and ddexitpop.css files.

The instruction state and I quote: Since the script also references two external files (ddbeforeandafter.css and ddbeforeandafter.js),
I make sure to upload these two files via FTP to a directory on my server first.

What directory on my server should I upload these file to? The pages are stored in the database so
I'm totally confused to where these files go.

Any help would be greatly appreciated.

Garry