Need to build a new rescue CD

I have a new sata drive that requires a patch to throttle back the speed on the drive as it cannot really run at the speed it says it can. So, I need to build a new rescue CD with a kernel with the patch on it so I can load the drive with the OS. Is there some magic involved here that I am not aware of? I tried just copying a new patched kernel over the “/boot/rescue” file on the rescue CD and it does not seem to like that. Is there some special command or procedure to build a “rescue” kernel as I’m guessing this kernel will need all modules builtin instead of having “loadable” kernel modules?