It’s easy, just go to WallPapperiPad.net from your iPad. Select a photo that you like, the image should open another window and display the full image. Hold you finger down on the image until you get a pop up, now you can save the image. After the image has been saved, go to settings, then Brightness & Wallpaper, tap on wallpaper, find the photo you saved, now you can set it as the home screen, lock screen, or both.
Note: You can save the smaller image but the image quality is not that good. Make sure the full image is displayed when you save, it will be 1024 x 1024 pixels.