With the adoption of PJax on Yii2 things have change quite a bit with GridView when it comes to work with them in AJAX mode. It will probably be confusing at the beginning, but then you will soon realize how powerful the new approach is.
There are two approaches to converting an Artisteer theme. The first is to simply copy an existing Artisteer – based Yii theme, overlay the CSS and images, then make any necessary tweaks to the layout files. This is undoubtedly the fastest route, but won't teach you as much as doing it from scratch. That's ok. Sometimes getting the job done is the top priority. The second approach is more general and will apply to some extent to other HTML templates that you may want to convert. I'll be covering the first approach in detail, while the second will be more of a general discussion.