Insert the rod through the brush bar and press the cap back on the end.

The hardest part is getting the end of the brush bar under that tight motor belt. Look for where it hangs up and use the screwdriver shaft to pull in an appropriate direction to allow the brush bar to slide a bit more through.

Once the bar is in align the small end of the caps towards the back of the vacuum (as shown)

When putting the cover back on, snap the front in first, then press the coin-operated tabs through their holes and turn with a coin.

Congrats! You don't need a new vacuum or expensive repair!