How do I delete pics on Lock Screen?

I have changed several pictures several times on the Lock Screen, and now every once in awhile a picture pops up on it which I don't want. Is there any way to delete the few pictures on there so thee is only one?

The only pictures that it is going to show are those that you directed to the lockscreen, go to the picture location and delete want you dont want anymore.

Also go to Start Menu > Settings > Personlization > Lockscreen and make sure you have picture selected for background as opposed to a slideshow.

TC :)