If you need to change the path, the version or any other setting specified in the project settings you will need to edit the project.

How to Edit the Project

From the Project Home page, select the pencil and checkbox in the upper right corner, Edit Project.

Select the Project Type tab

To Change the Version of Revit in the Project

If you need to change the version of Revit used for the project select update version. 

This will not upgrade models, it simply sets the version of Revit used to perform tasks.

On the Project Type tab, select Update Version

Select the new version from the dropdown, then Update

To Change All Other Settings in the Project

Select Edit                                                                                                          Make your modifications and update

Request Rescan and Check File Filters

After you have made changes go back to the Pencil and Checkbox and Request Rescan.

If you have File Filters set you will want to check those too