If you are coming over from Yii 1.x to Yii 2, and already read this guide, you may note that namespaces are very important in Yii 2 to identify classes. But do you know the list of seeded path aliases that come shipped with a basic or advanced app? Here is my attempt to list them.
So you want to use a fork of any existing vendor extension with your Yii 2 install and use the fork, instead of original source. This does not need you to push any update or register your package on packagist.org. You are recommended to follow the approach below:
I recently had to have a checkbox column in my grid view that supported the 'disabled' attribute. This was easy enough to do by extending the CCheckBoxColumn. However, I also wanted the checkbox to be selected when clicking on the table's row (supported via CGridView's selectableRows option). I discovered I had to tweak yiigridview.js so that it would not select disabled rows when clicking on it or on the 'select all' checkbox.