Yoga 3-1170 bios downgrade

[striimer]

Need help, put back older bios version.
Updated Yoga 3-1170 bios to the latest versionB8CN32WW, which is also only downloadable bios version on Lenovo site.
Bios Insydeh ver.5.42
http://support.lenovo.com/us/en/products...s/DS102768
Before update i've made bios backup copy with backup-tools.
Now i want restore previous bios version, enabled in bios flashback option, but which tool i should use for the flashing ?
Bios formats and sizes are different. Example inside results.rar the backup copy is x32_bios-region_10.0.30.1072.bin size 6144kb, 
when i extract from official site new bios version, after executing exe, insyde updater extracts bios with the extension .ECB, file name AIZY0210.ECB,
which size is 9676kb.
Backup-tools informed that bios is protected, code 280.
Or there will be any other way how to restore previous version ?
With early bios version i was able change variables, new version gives uefi error.