So for Franco Kernel, the dev does have an app, both free and paid. I have the paid app. Not sure what the limitations of the free app are, but check it out for free anyway. With the paid version, you can download the kernel and it will auto-flash it for you. Not sure if it is available on the free version.
Outside of that, you can flash any kernel in recovery just like you would a ROM. You don't have to wipe anything, though I like to wipe cache and dalvik cache after a kernel flash. Just a personal preference.
Also, the Franco.Kernel updater app has a boat load of ways to customize the kernel to your liking, with more options to do so available in the paid version.
Good luck!
jmar