If you look at step 5 of the post, we use $setup->addAttribute() to add the attribute to the database. You can use that same function to modify existing attributes as well. Just put in the attribute code that you want to edit and you can then make the changes to it that you want with the parameters in the array.
If you look at step 5 of the post, we use $setup->addAttribute() to add the attribute to the database. You can use that same function to modify existing attributes as well. Just put in the attribute code that you want to edit and you can then make the changes to it that you want with the parameters in the array.