First of all you must download a free copy of Bria X-Lite by following the link below and choose your preferred operating system;
Once you have downloaded and installed the application you will then see the below open your screen. Click the 'Account Settings' link to start the install.
You will then see the next screen where you will need to input your account information that would have been emailed to you.
Account Name: 'Your Business Name'
User ID: EP123456789 (endpoint provided to you)
Domain: phone.plivo.com (Domain/proxy provided)
Password: 123456789 (Your account password)
Please also check the 'Proxy' selection and enter 'phone.plivo.com' in the address box as seen below.
Then click 'OK'.
Now go back to the main application screen, you will see that your number is now active and you are able to make and receive calls using the keypad displayed.