The pieces for the conversion (tank, subframe, seat) are pretty expensive though, unless you can find them on eBay like I did and even then it's several hundred dollars once you buy the airbox, airbox lid, plastic, etc. If you are looking for a cheaper solution, the 2006-2008 KX 450F shrouds are a very easy way to update your look. They bolt up at the tank, and only require a couple of easy brackets to bolt the bottom two holes up. I used rivnuts on mine to make installation of the panels easy.
The fender is even easier. The 2015 fender (and later models if you like the style) bolts right on. The number plate matches the triple clamp mounting holes at the bottom, but they are both females. You can make some posts to attach them, or you can just use zipties. It bolts up at the top without an issue. I like the way Goliath came out, and I didn't have to mess with the tank mounting.