You run the cIOS installer in the homebrew channel like any other program. Preloader doesn't have anything to do with it. Also, note that you're not "changing" to IOS222, you're merely installing it alongside whatever else you already have in your Wii. And once it's installed, you choose to run your games from IOS222 in whatever disc or USB Loader you're running.
But as for Preloader you hold reset while booting to get into it.
Yet another edit: Wait, did you change the system menu IOS to 249 with Preloader? Now your posts are making more sense. IMO you should change it back to normal and just use a loader to boot your games. IIRC, games with the new error 002 won't run from the disc channel if you've changed its IOS around.