On our 2011, which had stacked Splendide units from the factory, there were brackets on either side holding the washer and dryer together. Removing the one closest to the exterior wall was difficult. A very small rachet driver did the trick.
The dryer is pretty easy to move as it's very light weight. The washer is much harder as it's quite heavy. Put heavy cardboard across the bed and you can slide/drag it across.
And yes, the doors to the washer/dryer had to come off. On our 2011, the path from bedroom to kitchen went through 2 pocket doors in and out of the bathroom. I'm not sure we could have gone directly out the bedroom door and down the steps.
It may be possible to tilt the washer on its back to work on it, after the dryer is out of the way.