My windows fell down.

I have opened up the doors on two windows. One fell down the other still works. Both motors still move. The one that fell down was taped back up. Now that I have time and opened them up I find that the wire for the window has come off of the white pully at the top.

I am trying to figure out how that happend but more importantly How I can get it back up. Will I have to take all of the braces and take the window up in order to get this wiring back into its pully so the window works again? Will I need to replace the regulator for this? Will I need to replace anything else?