KP666

So, I managed. I don't know really how, it was combination of reseting banks (Tab Button + Master Volume knob while launching on [yeah, what's the difference between "Master Volume knob" and "Tone Button", Line6, thanks...) and setting Amplifi into update mode and after an hour it worked well. After all - next time before I'll buy anything made by Line6 I'll check users opinions very carefully.

@Silverhead thanks for anwsers, they helped me to make one step forward. There is no useful information about whole process anywhere else. So, I've got drivers, got Line 6 Updater. I turn my amplify into update mode by turning it on while keeping A and C Buttons. I proceed my update and after a while all A-D buttons red-highlighted. In Line 6 Updater I get "An error has occured. Please try again" and: What is "Tone Button"...? I googled point 2. and found two Korean websites. For now I've lost four hours and I still don't have working stuff, there's no complete tutorial or guide, whithout @Silverhead help I wouldn't do a step forward. It's really annoying :( I'll have to think twice before buying anything else from Line6.