Stem removal
Just to go back to square 1. The bolt that goes down into the fork from the top of the stem.... Don't pull it right out, just unscrew it by 5-10mm and knock it down with a hammer (use a piece of wood to protect the bolt head). Repeat this step a couple of times to separate the expander wedge assembly http://www.robertscycle.com/hb-stem.html
Stem removal
Just to go back to square 1. The bolt that goes down into the fork from the top of the stem.... Don't pull it right out, just unscrew it by 5-10mm and knock it down with a hammer (use a piece of wood to protect the bolt head). Repeat this step a couple of times to separate the expander wedge assembly
http://www.robertscycle.com/hb-stem.html