Step 8: Install the lower headset bearings
Install the lower dustcap on to the bearing cup.
Install the bearings. If they are in a bearing retaining ring, slide that ring on to the fork and bearing cup. If they are individual bearings, install them into the headset bearing race in the frame.
Insert the fork into the frame.
Install the front wheel into the fork.
CAREFULLY turn the bike right-side-up, so that it's resting on its wheels again.