If you like to remove a custom area, there is not automatically in the list of Adminimize use the option of 'own options'. Each area has this option. So you need to decide in which would you remove them, like only at the Dashboard or about each page of the backend, then use the 'global options'. The difference is the loading. The global option load always inside the backend, the other ones load only at the defined page(s).

How you find the CSS selector, class or ID, look at this Wiki page and view the video, links for the topic.