There are several ways of doing this, but the way that makes your scripts easier to modify in the future is simply to add a global variable to your test script:
g_base_url = 'http://www.libraryinformationsystem.org';
and then open up the MyTest.objects.js file and change all references of:
"url": "http://www.libraryinformationsystem.org/Books.aspx"
to
"url": g_base_url + "/Books.aspx"
(and similarly for other URLs).
Then you can just change the base URL in either the script or pass through a value through the Rapise command-line or from SpiraTest (as a parameter).
Alternatively you can keep the script the same and just add the following code at the start of the test:
Navigator.Open('http://www.website.com');
or using a variable:
Navigator.Open(g_webSiteBaseUrl);