I have an older bike with threadless headset. I wanted to go to a threadless because there are more options out there for forks.
I purchased a Cane Creek S2 headset and a Nashbar carbon fork.
There is a local LBS that lets you use their racks and tools for $5 an hour.
I took my gear and went over. Just for clarity I am mechanically inclined, I have never installed a headset or cut a fork, or installed a star nut. Total newb, but willing to try.
Removing the fork and threaded headset are easy. Unscrew the quill, unscrew the brakes, remove the wheel, unscrew the fork. Then just insert the removal tool and hammer out the races easy. Viola. part one done.
Part two. Grab the crown race tool and POUND the crown race in. I was sweating thinking about my carbon fork. Set aside the fork. Use the headset press to install the head set races top and bottom. The wrench head told me not to worry that the races look crooked but they will go in straight. Works like a cork screw. Easy.
Set the star nut. Biggest POA ever!!
I used a ParkTools star nut tool for the job...40 minutes of hammering later, I need to be at 15mm and I am at 12mm. I read the instructions for the headset again to make sure that I was installing everything correctly. Yes I was. The instructions did say that I could use a screw driver in lieu of a star press. I decided to give that a go. One whack later and I was there at 19mm instead of 15mm.

I tested the reach of the top cap allen bolt and it reached. Good!!
Now onto cutting the fork. I ride with my quill slammed down so I measured the old fork and added about an inch or so. Made my mark and mounted the fork cutting tool from park tool and a hacksaw. In hindsight I should have used a pipe cutter. Anyway the top was a little wavy, maybe .5mms of dips and dives. I put the whole thing together with the spacers from my old fork and pushed the stem down to lock the crown race to the bottom race and secured it.
Now I need to get some cool spacers that will take up the space I have a .5 mm gap.
Lessons learned. When cutting a fork use a pipe cutter, Use the star nut tool to set the nut then hammer home with other device and check with a micrometer. Everything else went fairly smooth.
I asked the people at the LBS if they could use the fork and headset. Nothing wrong with them I just wanted to upgrade. They said that would be great.
LBS - Bike Farm - NFP helping people maintain the bikes they have to for transportation options. Nice people, nice place, nice tools. I will be going back for some other work I have to do.