Dangers of modifying a manufacturer firmware
The risks involved by reflashing a firmware are :
In case something went wrong during the flashing process (You should have to be very careful while it is flashing tho), The phone will be PERMANENTLY RENDERED unbootable, or you might PREMANENTLY brick your phone.
I strongly suggest you to not to try to do anything above if your device has a warranty from it's manufacturer, otherwise, You may confirm trying to attempt that.