Removing stripped head seatbelt bolt

So if you were me, how would you remove this 14MM head-stripped seatbelt bolt? What I've tried thus far:

• PB Blaster soaking on the bottom side (beneath)
• WD40 on the top side (I hate introducing the smell of PB Blaster into the cab, but I will if I have to)
• Hand held impact wrench/driver
• DeWalt 20V portable impact wrench

Doesn't want to move. Possible next steps: hammer on a 13mm socket and try the handheld impact driver again, cut a line across and use the flathead bit with the driver, or something much better that you'll suggest

 

Harbor freight bolt extractor socket. Super cheap and be out in 2 seconds

 

Weld another bolt to the existing head. The heat generated from the weld should be plenty break it loose.

 

it isn't a "special" bolt... center punch in the center and start with a sharp 1/8" drill bit, then the next size, then the next. If you mess it up you can always put a nut/washer and a longer bolt.