Like Corksport, I had my car in for repair under warranty (rust that wasn't fixed correctly the first go-round), so I only had to pay for them to weld the holes left by the emblems.
You can follow the how-to, but I've heard of some people having problems with it lifting, etc, down the road. Plus, if you live in a climate with any degree of moisture, or significant weather changes (like Canada), I'd be scared of rust starting prematurely in that area. For the peace of mind, I'd simply go with doing the welding; no matter what though, you'll have to do some painting and/or blending.