Customize Columns Order in Kanban View
Columns order is dependent on the Task Statuses order. So, change the statuses order, it will automatically change the columns order in kanban view. you can remove unwanted statuses also which eventually remove columns from kanban view.
Go to Settings => Customization => Layouts and Fields -> tasks.
You will see a settings Icon beside Status field. Click on the settings icon. There you will see all the available statuses. mouseover to the desired status and you can drag and drop at your desired position.
After changing the order of statuses, click on "Apply changes" button. Then, click on "Save Layout" button. Close the settings.
Yayyyy, Columns are rearranged as desired.