Under Families, click Autodesk Seek (for English versions of Revit) or Web Library (for non-English versions).
Autodesk Seek or the web library opens in a browser window.
In the browser window, navigate to the desired collection, and click the family or template to download.
In the File Download dialog, click Open to open the item in Revit, or click Save to save it in a specified folder, from which it can be loaded into a project.
If you opened a family and want to immediately use it in a project, do the following:
Click Create tabFamily Editor panel (Load into Project).
In the Load into Projects dialog, select the open projects to receive the family, and click OK.
The new family is listed under the Families node of the Project Browser.