Applying a kernel patch is a relatively easy process and the change can also be easily backed out in case of problems unlike support packs.
The process is as follows:
1. Shutdown the system
2. Stop any remaining process running from the systems exe directory such as CCMS agent, saposcol and sapstartsrv processes. You may have to do a kill -9 command on Unix.
3. Backup the existing kernel cp -pR /sapmnt/<SID>/exe/* /usr/sap/backupkernel
4. Uncompress the new kernel into the exe directory using SAPCAR (don't run the SAPCAR from the exe directory)
5. Restart the system and throughly test