How to delete all pictures off iPhone 4S?

I want to delete all pictures off my iPhone 4S though my PC. I have over 2, 000. Any help?

Plug the phone into the computer & under My Computer you'd see it pop up. Open it & you'd see all the pics. Select all & press delete.

That's it.

1. Open Settings app and then go to "General" followed by "Usage"
2. Choose "Photos & Camera" from the list, this will also show you how much space they take up
3. Use a left or right swiping gesture on the album to reveal a red "Delete" button