Combine Surfaces?

 From:  mat10x
8813.1 
Hi guys,

I'm wondering if I can join the 4 top surface segments into one whole surface on the part below.

I'd like to rebuild or rather combine the yellow highlighted segments and the main larger surface into one surface with no subsurfaces or Iso curves in it. Like a standard unmodified plane. Those smaller 3 surface sections just made a mess when trying to fillet in one shot. Had to explode and fillet manually.

Thx.