Step 1 - Locate the button on the front of the phone associated with "Sign In" and press it. 

Step 2 - Arrow down twice to highlight Web Sign In and press Select. 

Step 3 - A code will be displayed along with a website. Leave the phone as-is, and head to your PC. 

Step 4 - Open a web browser of your choice and go to the website displayed on your phone. In our case it's aka.ms/sphone - Once there, type in the code from your phone into the code area on the website, then click next.

Step 5 - Type in your email address and click next. 

Step 6 - Type in your password and press Sign in. 

Step 7 - If you've been greeted with this message, well done. Take a look at your desk phone and it should be logging into your account.