re-install/ new admin username

My website, Japanesebottleopener.com has been hijacked. There is malicious code on the site and my original username no longer exists for me to edit it from the wordpress control panel. Should I go to my host (1and1) control panel and delete the website and re-install it (I have a clean copy of the website on my laptop) and in so doing create a new username/password on wordpress? Thanks for any help.
Mike