How to install GridMarket child theme?

Hi, I've got WP 3.2.1 with Multisite, BP 1.5 and MarketPress 2.3.1 installed. My current theme is BP Default.

I've installed FrameMarket theme succesfully (I suppose). I downloaded the zip, unzipped all the content (ie the 'framemarket' folder) locally, and uploaded this 'framemarket' folder to wp-content/themes. Now it appears under 'Network Admin - themes' as well as 'Main site - appearance - themes', ready to activate. OK.

In both places, it states not to use directly but use a child theme instead. So, my understanding is that I need to install and activate the GridMarket child theme.

But now, following this: https://premium.wpmudev.org/project/frame-market-theme/installation/ in items 5 & 9 (You’ll see several files and folders depending on the theme package. Most themes contain a folder for the parent and child theme within the folder called themes & With FrameMarket you need to upload framemarket and gridmarket to wp-content/themes/), I should find a folder in the zip called 'gridmarket' but I do not. In the zip, there is a subfolder called 'gridmarket' under 'framemarket - themes', but its content don't appear to belong to a child theme (_inc, screenshot, style). I wonder if this is the folder I'm looking for. Obviously, this subfolder was uploaded to the server as part of the 'framemarket' folder that I uploaded.

Then, what should I do? Move this 'gridmarket' subfolder from 'wp-content/themes/framemarket/themes/' to 'wp-content/themes/' ?

Cheers,
Jordi