yes, copy the kernel to /
change permissions to 644 then at boot prompt type the name of it.
First you need to get the kernel that you want to install, then goes to Terminal app, and do this:
Code:
cd /my/path/folder/where/new/kernel/is
sudo cp mynewkernel /mynewkernel
sudo chmod 644 mynewkernel
sudo chown 0:0 mynewkernel
after that reboot and at boot prompt type "mynewkernel" or the name you give it. So try -v so you can see what's happens.
You need to be care of two things:
1. Don't overwrite the old kernel, so you can boot again into the system. if something goes wrong.
2. If you can boot whit the kernel, you need to check out later some issues, about System.kext version matching, usb, and othger issues.