Porting android kernel to new version of android

[Au]

So I've worked with building existing kernels, but never have I tried to port a kernel to a new version of android. I've started to gain an interest in porting kernels, but could not find anywhere a proper guide to assist me. Would I have to merge the changes of the new common android kernel with my existing kernel sources? idk. If somebody could point me in the correct direction, that would be a great!