Don't sweat the back filling. HA! Just a fair warning. Once the pool is full you can start backfilling. It is easier to get on it as opposed to waiting till the dirt becomes hard and clumpy. Make sure to put a few inches higher against the pool wall for water drainage away from the walls. I did all mine with a shovel and then a good ol buddy ol pal w/ a tractor came and barely scraped the existing good grass but enough to smooth what I had left to do. They only dug down to level about 8 inches, but their was still alot of dirt to move. They were also nice enough to take a majority of it to a low spot in my yard. Being zoysia grass it popped right back up after a month or two. Do trust, it will be a muddy mess until you either deck, landscape or grow grass back around. I am still cursing the dust bunnies. My perfect little yard is now messy, but we intend to start the deck next month.
Good luck