Help With Stripped Cap Head Screw



I need some help! About a year ago I installed my factory backrest mount and completely overtightened the cap head screws. Now I’m looking to change seats and cannot get the screws out. They are completely stripped. I tried using some extraction bits but they only seemed to round it out more. I’m at a loss…. Any help or suggestions are appreciated. I have attached a couple pictures for reference.


Help With Stripped Cap Head Screw