I'm running 10.4.5 on P4 630 and Itel D945 GNTLKR
I have my new mach_kernel ready, patched with only the base patch ( my setup is a P4 630 with sse3 NX PAE HT so I hope to gain performance by using the base patch only ).
Please, what are the steps to take in order to replace the old kernel with the new one?
I try to figure out by reading some other posts but couldnt get through with it.
Thanks

First let's say your new mach_kernel is named "mach_kernel.base" and is on the root. Repair permissions on it. From terminal do the following:

chown root:wheel /mach_kernel.base
chmod 644 /mach_kernel.base

Now reboot and and hit F8 to get the Darwin bootloader. Boot into single user mode -s. Run "fsck fy" and then "mount uw /".

Next type "cp /mach_kernel /mach_kernel.old"
Then type "cp /mach_kernel.base /mach_kernel"

Then repair permissions on the mach_kernel to be safe:
chown root:wheel /mach_kernel.base
chmod 644 /mach_kernel.base

Then type reboot and if all went well you have your new kernel. If for whatever reason it doesn't, hit F8 to get into the Darwin bootloader and type "mach_kernel.old" to use your old kernel to boot.