To edit the text in a Grimlock Navigation block like illustrated below, you’ll need to edit the right menu. Indeed, this block is used to display a WordPress navigation menu.
To edit this menu, you have to select the right menu in Dashboard > Appearance > Menus.
You can change the text displayed by editing the description. If the description area isn’t visible, please take a look at your Screen Options at the top right of your screen and make sure the Description feature is checked.

In the case you want to change the colors or the icons for this menu, please read the following topic: Colours in the “Featured-Homepage” menu?
Going Further
What icons can I use for my menu and on the whole site
A large choice of icons is available for your theme. Depending on the theme you choose, several icon packs may be available.
Creating Menus Showing Images
Thanks to the Grimlock Navigation Section, you’ll be able to add a menu displayed with featured images and texts to make it more appealing to your visitors.
How to Customize the “Cities” Grid Menu ?
To edit this section, you need to edit the “Cities” menu. Thanks to the Menu Image plugin and Grimlock plugin, this menu is displayed with featured images and texts to make it more appealing.