This installation guide describes how to install Linux Kernel 6.9.0 on Ubuntu Linux. This works with the latest version of Ubuntu Linux and most Ubuntu-based distributions including Kubuntu and Mint. The included kernel files have been compiled using the generic Ubuntu configuration. A low latency version is also available in the directory of the linked files.

Which version do you need? The same as the current installed OS
In the terminal run:
uname -a

Quick selection guide:

• AMD64 Most current computers
• ARM 64: ARMv8 CPUs
• ARM HF: ARMv7 CPUs
• IBM PowerPC 64: PPC64EL
• IBM Z: S390X

The files can be found at: https://kernel.ubuntu.com/~kernel-ppa/mainline/v6.9/

1. Download the general header package
   linux-headers-6.9.0-060900_6.9.0-060900.202405122134_all.deb
2. And the appropriate headers package for your system
   • AMD64:
     linux-headers-6.9.0-060900-generic_6.9.0-060900.202405122134_amd64.deb
   • ARM64:
     linux-headers-6.9.0-060900-generic_6.9.0-060900.202405122134_arm64.deb
3. and the kernel image
   • AMD64:
     linux-image-unsigned-6.9.0-060900-generic_6.9.0-060900.202405122134_amd64.deb
   • ARM64:
     linux-image-unsigned-6.9.0-060900-generic_6.9.0-060900.202405122134_arm64.deb
4. And the kernel modules
   • AMD64:
     linux-modules-6.9.0-060900-generic_6.9.0-060900.202405122134_amd64.deb
   • ARM64:
     linux-modules-6.9.0-060900-generic_6.9.0-060900.202405122134_arm64.deb

Install the files in the same order as downloaded above

In the terminal run: 
sudo update-grub

Reboot and select the kernel from the bootloader menu