How to install a custom kernel
* Requires root
Installing a kernel is done exactly the same way as installing a ROM, only you don’t need to wipe data, but it is recommended to wipe the cache. The most popular kernels are the Hydra kernels, Incredikernel & KiNgxKernels.
Install a kernel using ClockworkMod Recovery
First, make sure you have a good Nandroid backup, and Titanum Backups of all your data that you care about.
Next download your kernel to the root of your SD card.
Select “install zip from SD card”
Select your Kernel, and it will begin installing.
Install a kernel using ROM Manger
Make Titanum Backups of all your data that you care about.
Download your kernel to your SD card (You can also download some kernels directly from within ROM Manager)
Open ROM Manager
Select “Install ROM from SD card”
Select your kernel
Check only the backup option DO NOT wipe data
Your phone will reboot into recovery and start installing the kernel immediately.