[Plugin: Visual Composer] Replace tab text with images

I’m setting up a Partners and Clients page using Visual Composer. VC comes with a module called ‘Tour section’ (demo here), my idea is to replace the text in the ‘tabs’ with small images of the Partners and Clients’ logos. Any ideas as to how I would go about doing that, or something similar would be appreciated!

Theme: SkyDream 1.0.2
WP 3.5.1