you would swap out the sandbox URL to the live URL and secret/credentials with the new live credentials in your script. That's pretty much it. For most endpoints it is as simple as removing the ".sandbox." from the URL. for example
MERCHANT API SOAP "SANDBOX" ENDPOINT
https://api-3t.sandbox.paypal.com/2.0/
MERCHANT API SOAP LIVE ENDPOINT
https://api-3t.paypal.com/2.0/
This works for the rest API as well if I remember correctly.
here is the list of classic endpoints
and REST endpoints