Need to delete site, then rebuild from scratch

So I’ve decided to rebuild our word press site. Some of you may have seen some of my old threads about my super slow site that probably had a ton of malware that some “professionals” failed miserably to fix.

Well I’m over it, how do I go about wiping the site and all of its STDs off the earth then reloading what I need to rebuild? Even when I’m using the admin tools the site is slow and gives Trojan warnings. Thanks for the insight….