How to make Extended Kernel for NT 3.51?

[R1600]

Hi. Could anyone explain how to make something like Extended Kernel? I want to make Extended Kernel for NT 3.51 to run NT 4.0 NDIS driver. NDIS4 driver from NT4 build 1365 requires more functions in ntoskrnl.exe and hal.dll from NT4. (ntoskrnl.exe - KeInitializeTimerEx, KeSetTimerEx & hal.dll - KeAcquireSpinLockRaiseToSynch)
I have modified a bit of assembly file with Hex editor and IDA. But due to lack of my knowledge(and also my English skill), I still need some guide how to make Extended Kernel.

I have looked up other topics explaining how to make Extended Kernel, but I failed to understand the whole process. Is there anyone who can help me?

[Damnation]

@R1600

This is an XP ntoskrnl extender - https://github.com/MovAX0xDEAD/NTOSKRNL_Emu

Take a look at how it works and then try to apply that to NT3.51