Originally Posted by
Kontact
That's a quill stem setup.
Put the allen wrench in the bolt and loosen several turns. With the allen still in place, rap it with a mallet to push the bolt down. This will loosen the wedge the bolt is connected to that is down inside the steerer tube. Once it is loose, the stem can be pulled directly up and out for greasing.
What he said, I like using a hammer on a block of wood, maple is my favorite, goes without saying, make sure the head of the bolt protrudes above the stem.