With the help of the link How Do I Install/Upgrade/Uninstall an AppExchange App, you can easily understand how to install/Upgrade/Uninstall the app from the AppExchange.
PS: View Metadata Search, Salesforce quick search app on Salesforce AppExchange: https://appexchange.salesforce.com/appxListingDetail?listingId=a0N30000009wgF7EAI