Download the Official TWRP App (root required):

• Play Store (recommended)
• No Play Store? Download the latest version here.

Install the app and open it. Agree to the Terms. Select TWRP Flash. Select your device from the device list ({{ page.codename }}) and choose a version. The file will download to your Downloads folder. Browse to and select the file. Tap on Flash to Recovery. Find out more about the app here.