If there is an archery shop in your area, they should have a commercial arrow straightening device that will work on that bent arrow. Basically it is 2 sets of rollers that can be adjusted in width to accommodate straightening the bend. A kinked shaft = rollers closer together. A slightly bent shaft = rollers farther apart. There is a lever mounted in the center of the device that pushes down on the shaft on the bend to complete the straightening process. Many of the devices have a dial indicator on it to show where any straightness imperfections are in the shaft.
Otherwise you can straighten the shaft with the typical heel of hand pushing against the bend just using more force than with wood shafts. Hope that helps.