Doing a little housekeeping today, and I noticed that my staff seem to be clicking the "add new column" button a lot in Kanban view. Each time they do this, and drag an opportunity in, they're creating a new stage. So I now have a LOT of duplicate stages.

For example: I have 4 "Won" stages each containing hundreds of opportunities.

Is there a way I can mass move opportunities to a stage? If so, I can delete 3 Won stages (for example) and move everything to the remaining Won stage.