Exactly what I was about to suggest. Fiirst remove the headshell holder, then remove the tube from the pivot. Get the closest diameter spring type tube benders from the hardware and slide it over the arm. It might not go past the bend but should help return the tube to a circular shape as you bend it back. Keep slipping the spring tool over the bend as you go.
Carve out a groove in the top of a Cork, the same Radius as the Arm. Place it under the Bend....Then CAREFULLY Press Down on the Arm where it is supposed to be bent...And Pray....Until it is Straight, or Cracked...Good Luck..

Looking at the way that arm is bent I can't help but have concern for the arm pivot bearings. Would have been under some kinda stress.