Koi Pond Removal - How?

My wife and I are closing on our first house a week from tomorrow. First on the list is to remove a koi pond in the backyard. As I understand the previous owners twice removed filled in a pool and put in this koi pond with a beautiful water feature. The first winter after installation there was an ice storm that pulled the double whammy of felling a tree knocking out power to the pumphouse and freezing/bursting the pipes that fed the water feature. Some things aren't meant to be. It's now a home to some rather large bullfrogs which have thankfully kept the mosquitos from turning it into a brothel.

http://imgur.com/a/CELUz

Here's what I know:

It's approx 12 ft across and maybe 4 ft deep in the middle. The liner looks to be fabric, not plastic.

I have access to a pump and there is a creek on the north and downhill side of my property (win!)

My research tells me these are steps I need to take, are they correct?

• Drain pond
• Cut liner in various spots to prevent refilling
• Fill-in bottom of cavity with as much large and solid material as I can find. (You can see the large rocks/boulders surrounding the pond, I'll start there and then move to the hundreds of 2-10 pound rocks that dot the property and the gravel that lines a former dog kennel.)
• Once I've run out of large solid material, continuing filling with sand until it's about a 4-6 inches below the surface of the surrounding yard.
• Top it off with a crown of topsoil that should settle, hopefully to level with the surrounding yard.

Anything I'm missing? Anyone ever done this before?