Well...the "how to do it?"-part is pretty much covered by tj_cool's link. I'm more interested in the "why"-part. Why do you want to softmod your wii?
Sure, there's plenty of advantages to be found (just read around on this site), but there are disadvantages as well:
-brick risk: the abovementioned guide is pretty failsafe...if you follow it correctly. However, it can never be completely excluded. And softmodding voids the warranty, so if something goes wrong, you can only blame yourself.
-time: though apps like sciifii look promising, I don't believe in the "silver bullet". There will always be exceptions, quirks, incompatibility, weird behavior and/or bugs. If you're going into softmodding, familiarize yourself with the technical terms and learn about what they all mean. That way, you can fall back to your knowledge in case things go wrong (usually it's the other way around: by knowing what things are, you can prevent them from going wrong in the first place).
-legality: softmodding's a bit shady. While technically legal (in most countries) to do, you can't deny that most appliances and/or use are downright illegal. That can be tricky sometimes (just yesterday, I spent half a day getting sneek to work).
In case this looks saddening: that's only because I list the disadvantages. The advantages, on the other hand, are so plenty that I don't even bother to count them.
Christopho said:
Also, I recommend a USB Loader, saves money, load times, etc.
I agree on the USB loader, but...it doesn't save money. It's still more expensive than a few DVD's, so if the goal is to just keep a backup of a couple games, I'd say the DVD option is cheaper. If however, the goal is to keep a backup of the entire collection of games (or if you plan to pirate games), then an USB loader is less expensive in the long run.