How to delete wordpress multisite?

Hello Admin,
What if i will deleted everything and start to install again the wpmu dev dashboards?
My question now is how can i delete everything my wordpress multisite?
it so happened i wanted to create a new installation since i noticed that i am experiencing a hard time to re-activate again since i accidentally deactivated my super admin account.
So that i can easily start a new..thanks a lot. hope you respond.