How to make modified BIOS work on Intel Boot Guard enabled device?

The Dell Alienware X51 R3 which have MSI manufactured Z170 motherboard , and I am modifying it for kaby/coffee lake support.
But after I flash BIOS , it doesn’t boot anymore.
I found Boot Guard was enabled.

Is there is any way to make Intel Boot Guard disabled?

@dsanke , to confirm, please check MEInfoWin.exe -verbose
Is that where you checked? If not, run that and check Measured + Verified Boot both enabled on left/FPF side at bottom of report. If both enabled there nothing you can do except replace PCH with one that is clean and does not have burned in signature to FPF fuses.
If they are disabled at left/FPF side of that report, then Boot Guard cannot be enabled properly (Thus can have no effect, even if enabled at BIOS or MW FW level). I have had user check this once before recently on this model, it was enabled like you said, but always best to check as sometimes it might not get setup correctly…46011#pid146011

If you find it disabled at left/FPF side in MEInfo report, then some other reason for your bricked BIOS - if this is case please upload for me your original file and the one you edited

Please also show me image of output of >> MeInfoWin.exe -fwsts

I see there are both "Enabled". (2.09 KB)

@dsanke - nothing you can do then with the BIOS until you replace PCH with a clean uncommitted PCH (no hash burned in fuses, ask specifically for that if you order from some China seller).
Some BIOS, certain areas can be updated/edited, but usually these are not areas we modify as a BIOS modding thing. You can see which areas may be editable w/ UEFITool NE, anything not in a yellow, cyan, or red region can often be edited.