How do I delete ALL photos & Albums from my iPhone 5S?

I want all pics gone...albums, camera roll,etc. Already backed up to PC

1. Initiate the Photos app.
2. Select all of the photos
3. Delete them by tapping on the trash can icon at the bottom of the screen.

Alternatively, you can login to your iCloud account, select the Photos icon and then mass delete them from there.

You delete entire albums as well. Let me know if you need help.