How to delete published article

Hello guys, I'm a newbie here. I just need some help regarding with my published article that I posted awhile ago.

I wanna ask if how to delete my post and replace it to a new one? Maybe put some revisions on it. Can I still replace or delete it or not? Because when I checked my notifications it already been published.☹️

I hope you could help me with this issue. Thank you and God bless us all.😇