To begin installation the ScreenSteps for Salesforce application please visit the App Exchange:
Get It Now
Click on the Get It Now button. You can then choose to install in production or sandbox.
Confirm and install
A screen similar to this should appear after you login. The only real difference you may see is the version name/number and the description.
Choose Security Level
Use the default security settings (admin only\P and click Next.
Click the Install button.
After a few moments you should see a screen similar to this. At this point the installation is complete and you can move on to configuration.