Trouble with the split solid tool


I am a student learning Grasshopper.

I am currently working on recreating the egg chair for a project. I am almost done with it, but the Last step I need to make the chair is not going through. Can someone explain to me how to split a lofted extruded surface!

Thank you!

Grasshopper sheet|690x380

It probably helps if you describe in more detail what issue you are having. The file with the problem would also be helpful