To fix this, activate the user and change their email to yours so when you reset the password it is sent to you. Reset the password with the button on top of the user page. Once you receive the password reset email, log in as that user and go to their My Personal Custom Reports folder in Reports. Find the reports and dashboards you want and save them to a "public" folder.
To change the Dashboard Running User, edit the dashboard and select the View dashboard as drop-down at the top right-hand of the page. We recommend choosing "Run as logged-in user" because it will only show the user the data they have permissions to see. This also ensures you can run the report and dashboard even if the user who created it becomes inactive.
Note: We recommend not saving anything to the My Personal Custom Reports folder that you want others in the organization to view.