How to edit priority of an issue on the Kanban board?

[Christie Phan]

I want to be able to edit the priority ( trivial, minor, major, critical) of an issue on the Kanban board.  Use case: As a project manager, I want to be able to prioritize the tasks by Trivial, Minor, Major or Critical based on each Assignee before the start of each Sprint. It would be perfect if I can click and drag the issue into a priority column and the priority updates. 

[Nicolas Bourdages]

You have to edit the issue and change the value in the Priority field. Drag & drop is for status changes only.