I'm honing my technique. managed to get a couple more out tonight. Drilled through, heated with oxy acetylene, (didn't try and burn it out) then used welding, similar to before. I ended up with the remnants of one well down the hole, and used a torx driver as an eezi-out and got it out using an impact driver.
I also adapted a small bench drill (drill press) so it clamps on the deck face to drill straight down through the stud.
Learning something new every day.
Mart.