Backyard Pond - How do I properly fill it?

I'm looking for guidance on how to proper fill this backyard pond. I found youtube videos on how to fill natural ponds for a house in a rural area but nothing on a concrete lined pond in a backyard.

16 ft long x 10 ft wide x 2 ft deep (2.5 in some corners)

Location: Northern California/ Central Valley

Goal: fill the pond and build a turf putting green.

Advice I have been given: smash up some of the concrete on the bottom then fill it up. It sounds so simple lol

My questions:

• how much of the bottom layer of concrete needs to be broken up?

• how would you layer the dirt and (i assume) gravel? Size of the layers?

Seems like a straightforward project but would appreciate any advice. I'm a new homeowner so I'm hesitant to approach a big project like this.