1. Go to Salesforce CPQ Installation links to get all the packages available for Salesforce CPQ.

http://steelbrick2.force.com/Installcpq

2. If you are installing in Production or Developer org, please select production otherwise select sandbox as the installation link.

3. After you select the installation link you will be navigated to the Salesforce login screen.

4. Once you log in successfully, you are presented with the Security Level Selection page.

5. Install for admin only if you don’t want to grant access to all users. 

6. Salesforce recommends granting access to all users. Choosing other options can lead to extensive time spent adjusting permissions later.

7. Select the correct option and click Install.

8. Salesforce CPQ then prompts you to approve Third-Party Access.

Third-Party Permissions

Select grant access to these third-party websites and click continue.

Salesforce CPQ Installation in Progress

Salesforce sends you an email once your installation has completed.

You can go to Setup | Build | Installed Packages and check if the package is installed successfully or not.