Option 1:
Open the Start screen from the menu and go to Settings -> Applications -> Application Manager. Here you can see the same in the first tab "Installed Apps" all applications you from a market such as the Google Play store installed on the Sony Xperia Z5. The Apps are sorted alphabetically here. Find the apps that you want to delete from your Sony Xperia Z5 and click once on it to display the information map of the App.
On the top right in the corner you will see the "Uninstall" button. Click it once and the appropriate app is completely removed from your Sony Xperia Z5. Proceed as follows for each additional app.
Option 2:
Open your Sony Xperia Z5 the Google Play Store and go to "My Apps". Here you can see now on the first tab, the installed apps. Proceed as with "Option 1" on an app and then in the window that opens on "Uninstall" to complete by the delete so the application Sony Xperia Z5.
You now know how you can delete on the Sony Xperia Z5 an app when it is no longer needed.