Step 1 - On your phone, find and press the button associated with Sign In.

Step 2 - Now, press 2 or arrow down and select Via PC.

Step 3 - We're done with the phone now, head to your PC. Open Skype for Business by opening start and scrolling down to the Ss.

Step 4 - When Skype for Business opens, it should greet you with a second password prompt. Enter your email twice, type in your password, then press ok.

Step 5 - All done. Head back to your desk phone which should be signing in.