remove wp-admin link from website

I want to remove this link from my website, in the interests of looking more professional to potential clients. I used to be able to do this quite simply within WordPress, but can’t find a way to do it now. All the previous comments in this forum are at least 3 years old, and don’t seem to relate to the current version of WordPress. I am using Thesis 2.
http://www.flloydkennedy.com

Any suggestions most welcome.