Good you got your MOT sorted, I would suggest you do get it fixed though, it's a critical part.
I agree with shifty, don't hit them, the bearing is not designed to take that sort of hard shock, shaft and bearing may not looked damaged that that's not to say you haven't just knocked 10000miles of it's life. The bearing in normal operation doesn't have to endure large laternal forces, it's design will suit radial forces.
Two hammers and at the same time, strike the arm either side of the shaft to shock it off, what you are actually doing is causing the metal around the shaft to go oval, opening it up enough that it will enventually just fall off the shaft.
It is critical that you hit both hammers of the SAME size at the same time, thus minimising the forces on the steering box.