They've been preparing for about a year. They built the new supports, then the tracks, then the mechanism that shoves it into position.
The movement is imperceptible, inches over time -- that 1.5 minute video cover about 15 hours of real time.
There will probably be better video released soon. They just moved it last night.
Apparently it isn't the longest or heaviest bridge that has ever been moved but it (I think) is the most complicated because the bridge was falling apart and it winds through a residential area.