Compiled Kernel Install

[FabioGenesy]

Hi,
following your guide, I was able to compile the kernel to which I made some configuration changes.
To install it on a board where Lubuntu is already present can I simply replace the Image file or do I have to do anything else?
Is it necessary to do these operations as well?

sudo make modules_install
sudo make firmware_install
sudo make headers_install INSTALL_HDR_PATH=/usr

Thank you very much!