To customize the Giant Board kernel you first want to run the build menu command
On the first build of the kernel select option 4 to download and prepare the kernel.
After selecting option 4, the automated script will download the kernel and begin patching some various items needed by the Giant Board. Once that is complete you will be presented with the kernel config menu and should look something like the image below.
In this menu you can enable and disable all of the Giant Board kernel features. Once you’ve made the changes that you would like, you can select exit and it will ask you if you want to write your changes to the .config file, select yes. From there the kernel should continue building and notifiy you when its complete.