They came in yesterday and I went ahead and assembled everything. The baffles are easily the only difficult part (I'm not sure why they don't come pre-assembled), but if you do the baffles before when you start, they aren't that hard to do. When you get them, the heat shield aren't attached, so you have to place them on the pipes prior to putting the baffles in (but don't fasten them down. Slide the baffles in - matching the holes up. The bottom heat shield on mine had to held in place in order to match the holes up, but nothing too hard. Once the baffles are on, just fasten everything down and you're done with assembly. However, they do not come with a head flanges, so you'll have to use the stock ones. They are gorgeous. I haven't started mine up yet to hear it, but in terms of ease of assembly and looks, they are awesome. When assembling, make sure you have a towel or blanket down. I got a tiny little scuff on my heat shield while assembling.