Creating full backup of WRT1200AC V2

This will be helpful for me also, I uploaded a backup but al of my installed packages are gone.

I see on the wiki this will be correct and you can add or remove packages in configuration/open list.

But how does this works?
I like to make a backup with my packages but how, is there a guide step by step?

I found this Backup from LuCi including added packages and their configuration? - #4 by hnyman

But how to make a script like that?