Open the Settings app
Tap Wallpaper
Tap Add New Wallpaper
Choose a wallpaper from Photos, People, Photo Shuffle, Emoji, Weather, or Astronomy
Adjust the image if needed
Tap Add
Choose Set as Wallpaper Pair or Customize Home Screen
Tap Done
To change an existing wallpaper, press and hold the Lock Screen
Swipe to a wallpaper and tap Customize or the plus icon
Select a new wallpaper and save it