If you want to delete all of your Picasa photos from your Note 4, here’s how:

  1. Open the Photos app on your Note 4.
  2. Tap the three lines in the top left corner of the screen.
  3. Select Albums.
  4. Tap any album to view its contents.
  5. Tap any photo to view its details (if it has any).
  6. Tap the trash can icon next to the photo you want to delete.
  7. Select Delete Photo from the pop-up menu that appears (or press and hold on the photo until a menu appears with Delete Photo at the top). ..