1. Log into your PayPal Business Account
2. Click the wheel between the notification icon and the Profile link.
3. Click Profile and settings
4. Over to the left select My selling tools
5. Find the API access section.
6. Click Update
7. Scroll down to the NVP/SOAP API Integration section
8. Click Manage API credentials
9. Click show to see the API Username.
10. Click show to see the API Password.
11.Click show to see the Signature.
12. After you have copied the username, password, and Signature click done.