Just proceed with the guide, modmii is working just fine, it's you who isn't following directions and/or have decided you don't want to repeat steps (even though I suggested an alternative which doesn't involve repeating steps, more on this later). If you think you know what you're doing, which clearly you don't but w.e, you can launch the wizard, and answer the questions honestly (i.e. Tell it that it isn't your first time modding your wii) this way when asked if you want to install/update the HBC and bootmii you can say no.... or, you know, just do what I said originally and skip the step when you get to it. Guaranteed if you go down the road of answering honestly u will have more questions and probably won't feel comfortable proceeding.
So, maybe I talked some sense into you and you are prepared to proceed with the modmii wizard as if your wii was a virgin... remember when I said it was fine to repeat steps? Enter any Mac address, doesn't have to be your own if you are too lazy to check it, (or select any disc based exploit instead of wilbrand, doesn't matter since u don't need an exploit given your circumstances), then, when following your guide, read and follow the note that says if you already have the hbc installed, you can use it to launch the hackmii installer instead of an exploit (or skip the step entirely if you think you know best and are confident you are running the latest HBC using IOS58, it literally takes less than 2 minutes to run the hackmii installer and update the HBC and bootmii)
If it's too much for you, you can use modmii's syscheck updater, in which case it will detect what mods are already in place so you don't have to repeat any steps (as I stated originally before you complained about repeating steps, I guess u didn't read my advice too carefully did you?). Mind you, you could have finished 10 times over by now even with repeating steps, but fine, you don't want to reinstall the homebrew channel, don't, use the syscheck updater. Btw, just because u have the HBC installed doesn't mean it's the latest version or running off of IOS58, so you may end up reinstalling it anyway.
If this is too much for u, then honestly any guide is probably too much for you and you should just give up or find someone else who can help you follow directions. But if you truly believe you can handle this but don't like modmii, that's cool, use wii.guide
Good luck and peace out
Edit: when you reinstall or update the hbc you won't lose any of your current homebrew apps. Those are not installed directly to console and are saved to and loaded from sd:\apps or usb:\apps
Edit2: I rarely lose my cool, somehow you got under my skin a bit, don't take it personally, I'm already over it
