I finally got the truck bed loose. I applied a liberal use of grinder and BFH and voilà, all four anchors came out. Hopefully tonight I will finally pull the bed off the truck. Also I highly recommend 3M 982C Cubitron sanding discs. They are expensive but Jebus do they cut and last a freaking long time. Bonus Corgi and sleeping Corgi and Great Dane for your time.