XF 1.5 Changing Elements based on Permission

I'm using Audentio's #Rekt (http://www.audentio.com/demo//xf/index.php?misc/style&style_id=48) theme, and quite like the welcome block part, so I kinda wanted to keep it to make the board look a little less plain, but obviously when users are browsing and signed in, you don't want a big "SIGN UP NOW" button.

I was wondering if it's possible, and how, to edit the templates to show the the welcome block with certain elements removed to certain user groups. So if I enabled the perm to view on all users, while unregistered get the whole shebang, and normal users will get the banner image, the "Welcome to X" text, and the little text below it, but not the big red button.

Bear in mind I have very very limited knowledge in CSS and the template syntax beyond seeing what some statements do.