you need to take the steering stem out by removing the handlebars and the front wheel and unbolting the front brake caliper,the steering stem is held in by some big castle nuts under them is the bearings,one at the top and one at the bottom.The bearings are likely to be ok though ,its the bearing cups and cones that wear they get small grooves in them and dents where the ball bearings wear on them.why are you changing them? if its because there is some play in them you can just adjust them and it will go away ,if its because they stick in a certain place then its the cups and cones you need to change.
adam bike doctor
May 2006