Suzuki RM-Z450 Owner's Service Manual page 277

17-20 FRONT FORK AND STEERING
• Remove the handlebar holder set bolts and nuts.
• Remove the steering stem nut with the special tools.
" 09940-14911: Steering nut socket wrench
09940-14960: Attachment
• Remove the steering stem lower bracket.
NOTE:
Hold the steering stem lower bradcet by hand to prevent it from
falling.
• Remove the upper bearing.