Dahua DVR1604HF-U-E how to apply firmware update?

I have a Dahua hybrid DVR1604HF-U-E. Vender sent me firmware update package with the following files:

• 
  custom-x.cramfs WinImage 5 KB
  flash.bin BIN file 16,384 KB
  General_DVR5X16_Eng_PN_V2.200.0001.24.R.20141114.bin BIN file 13,607 KB
  Install.lua LUA File 9 KB
  logo-x.cramfs WinImage 5 KB
  romfs-x.cramfs WinImage 12,089 KB
  u-boot.bin WinImage 218 KB
  update WinImage 13,517 KB
  web-x.cramfs WinImage 1,421 KB
  

How should I apply the update to DVR? I tried copying Genereal_xxx.bin to a USB thumb drive, renamed it to update.bin, plug in DVR, then went in the DVR menu info-> version -> upgrade, but got error message "update failed".

the message should be wrong model