Remove Previous Post/Next Post

I am trying to remove the previous post/next post area right above the “leave your comment” area”. I would also like to remove the lines. I have tried every single snippet of CSS that I have found in other threads and nothing has worked. I have tried adding them to the custom CSS area of my theme as well as trying it in a plugin I installed called SimpleCcustom CSS. Nothing has worked.

The page I need help with: [log in to see the link]