1. From the main menu find the "Settings" app and tap on it.
2. Once opened, tap on "General" which is found along the left side of the screen. A new menu will appear on your right with the option of "iPad Storage". Tap on this.
3. Here you will see how much space is left on your iPad and a breakdown on each apps usage. To quickly remove storage from unused apps tap on "Enable" under the "Offload Unused Apps" heading. Or select an app that you'd like to remove storage from the list below.
4. Here you can "Offload App", which will free up storage but will keep your documents and data if you want to re-download the app in the future from the App store. Or alternatively you can delete the app which will remove all documents and data.