AJ has it right, the steering clutch sits on a lip on both sides. Usually a few smacks with a hammer and a wood block (so you don't damage the brake drum)will loosen them up. Too, a good pry bar levered against the side of the drum, often in conjunction with a shock from the hammer, will usually do the job and free things up. From there the drum and clutch assembly should lift right out.
One thing, just make sure when your lifting it out that the clutch doesn't slide out of the drum. Usually it will try, and once it starts out, the whole assembly will lean to one side, and just make matters worse. If the clutch pack does fall and hit anything it will, more than likely, bend the ears on the discs, and pretty muc ruin them. In other words be careful. Good luck.