nand flash chip is very sensitive to high temperatures.
Unfortunatelly no one wants to take this task. After some research it's found that NAND chips are very sensitive to high temperature. Most probably data will be lost after IR/hot air heating. I'm still searching someone to do this for me.
Some specialist told me, that there is very high possibility destroying data during soldering - so no one will take this task. But fortunatelly he fixed my old, broken phone.