200+ kgs is not something to try to lift on your own, and definately not down some stairs!!
An engine-hoist on wheels would b e useful to begin with. 5 steps would make a height difference of about 75 cm wich should be possible to slope out using a couple of 2x4s temporarily nailed together and supported by the steps to avoid bending. Then using a rope and blocks would make the travel down the slope well controlled I think. But still not a one-man job as guiding, pushing, trimming and looking out are best done by more hands and eyes than just two of each.
Not to mention that company always makes a task more pleasant

Keep us updated on progress, this is interesting!
BR
/Peter