Either open each photo individually and at the bottom right there's a little garbage can icon, or you can bulk delete by tapping Select at the top right in All Photos, and then tap the photos you want to delete. It will allow you to select multiple photos and then give you the option to delete them.
As a side note, I can't remember if this is a new thing in iOS 9 but from All Photos, tap the back arrow up in the left corner where it says Albums. Scroll down in Albums and there is a "Recently Deleted" folder. You'll want to clear that out too if you want them gone like right now.
12-24-2015 12:18 PM
