I believe you are talking about deleting the stubIOS249 which Nintendo planted in the 4.2 update to stop hackers. Don't worry, this isn't an actual IOS so you can't brick by deleting this. If you follow this guide here; http://www.wiihacks.com/recommended-...tem-menus.html
It will show you how to delete stubIOS249 and install the real IOS249. If you follow it step by step then your softmod should go smooth.
Hope this helps!