Select Salesforce & HipChat Connector from the integrations list.
In the next screen, select a specific room to install. Note that Global (all rooms) is not supported.
Click Add Integration, and in the popup, click Approve.
Click Sign in to Salesforce.
If you're not already logged into Salesforce in your browser, you will be asked to enter your Salesforce credentials. If the authorization was successful, HipChat will show You are connected to Salesforce.
Optionally, repeat steps 5 and 6 for all rooms you wish to install the integration.