How can i modify this theme?

[saurobronto]

HI, i have installed Earth theme from http://www.votre-ecommerce.com/theme-prestashop-hearth-gratuit-ecologique-biologique-292
I would like modify some little part in that theme, but i'm a beginner and also i'm running a mac.
For modify my files i'm using Smultron, and for ftp, FileZilla.
My prestashop is v. 1.2.5 under linux hosting some file are correctly modify at 777, including this theme.

my site is this: www.zirtago.com, and from the Earth Theme i would like to remove the big brown buttons "HOME CART MY ACCOUNT SITEMAP CONTACT" that I don't need it, due the links are already on the site...on top. If you can also explain what program i need to use to find that part to modify would be nice.

I'm using the new browser chrome x mac, so under the inspection i'll see the interested part is starting a the blu line on this screenshot, but i'll ignore witch is the right file to modify.


Would be nice if some one can tell me also how to remove the empty square logo on the left sky.

Thank You!

Sauro