It also took so long because they had to:
1) Get the equipment for dismantling the ride inside the building.
2) Put such equipment together
3) Dismantle the track from inside the building.
4) Remove the pieces
5) Bring in the new pieces
6) Assemble the new track pieces
7) Dismantle the equipment
8) Remove the equipment
The extra long time is due to being confined within a closed building. A lot harder to do than when you have the endless height of open sky to work with.