How do I do this?

With some work and disabling auto placement on the slurs, you could make the slurs look like this. It will get rather tedious but can be done. At first glance, I would say you need 5 slurs for the top line, you may find you need 6 once you start doing it though.

Edit: also you can add a staff to the piano in the instruments dialog (press i) so there are 3 staves. You will also need to be familiar with cross-staff notation and tuplets to make it happen.

Since this is a fixed score (once you'll have transcribed the notes nothing will change) I would rather export as pdf and draw the slur over the pdf. Hope you don't have too many pages like this one though ;).

Just curious, where does it come from?