You don't disable that kind of integrity check, you simply set the checksum. The one that's relevant in this particular case is the respective field in the
IMAGE_OPTIONAL_HEADER, that is
That said, you will likely run into additional issues once you resolved this one. I am not sure if the kernel itself is subject to Early Launch scans, but I reckon there's a reason why these binaries are also code-signed. So at the very least you may want to disable the integrity checks altogether from an elevated prompt:
bcdedit.exe /set nointegritychecks on (make sure to reboot afterwards). Another point to consider is UEFI with enabled Secure Boot. In this case the Windows boot manager will somehow check the images it's asked to load. But since details are missing, it's not clear if this might be the cause of the issue.
Various functions can be used to compute a checksum for a PE file. The probably easiest method is using the Image Help Library function
MapFileAndCheckSum() or alternatively (
CheckSumMappedFile()). If I remember correctly there are a few more, including one
Ldr* function from
ntdll.dll which can be used to that end.