1) Standing beside your side mirror and looking at the bottom portion of trim on the inside edge laying on the windshield, slide your fingers underneath so you are pulling it toward yourself and lifting approximately 1cm off the glass, so you can just get your fingertips underneath. Then pull vertically upward to release the trim. It takes a good effort, but be controlled, because you don't want to reef on it and bend the strip. You will hear a "pop" as the first clip releases. Then work your fingers along the strip, popping each clip until you have release it all the way to the back of the car.
2) Once off the car, find some space to work. I used my truck tailgate and the back patio table. Start peeling off all of the loose blackout covering that you can. In my case, most of it on the roof was barely attached. Strangely, on the area covering the windshield, it was solidly on (woulda thought years of wind and road debris would have made it the opposite...) You'll notice that there's a lot of old adhesive residue... more later...
3) I used a razor blade cutter, a razor blade scraper and my Dremel drill with a mini sanding wheel. Very carefully, and I mean CAREFULLY, with FRESH blades, I first cut a slice along the very edge of each side of the trim. On the outer side where the rubber meets the edge of the strip, I left a good 1mm of old blackout on it (you will see later, don't get too too worried about getting too close to the edge...) On the inner side, you will see that you can wrap right around to the bottom edge of the trim before touching rubber. Again, I didn't want to cut the rubber, so left just a fraction of old material in place. You don't want to cut the rubber.
4) Once I had made my lines on either side, I used the razor scraper and worked from one end to the other and lifted as much off as I could without much resistance. If it's not coming off relatively easy, leave it, we'll get to it shortly. Just get whatever has been loosened by having previously scored both sides. And don't try to force the scraper. All you will do is dig into the aluminum and leave sharp divots which you'll have to sand down later. You're just trying to clean up as much as you can before the next really MESSY step.
5) Now we get messy. Get some eye protection. You will need a Dremel or other rotary tool, a Sanding band (NOT a grinding wheel) and preferably not a Coarse grit, but instead a Medium or even better a Fine grit band. I used a Coarse grit initially which worked great at stripping the blackout off, but it's hard on the trim underneath and if you're not careful, you'll make gouges in the trim, or even worse, the rubber running alongside it. I laid the trim on my tailgate so I had a nice long flat surface, and I began sanding. TAKE YOUR TIME, DO NOT RUSH THIS. It's not hard at all, but so easy to make a mistake with a rotary tool. This is also the step where you TAKE YOUR TIME and carefully work up to the edge on either side and sand down (as in a bit of a bevel edge) the remaining blackout tape which you had scored in step 3. Did I mention DON'T RUSH? I also found I could fold the rubber on the inner side back with my thumb as I ran the dremel along the side.
6) On the end that meets the windshield, there's a large chunk of rubber around the end of the trim. VERY CAREFULLY, I found that I could work the rubber away just enough to get the edge of the metal strip. I would suggest a second pair of hands for two minutes would become useful here, but I did do it myself. Don't pull too much, because the rubber will of course tear. And keep in mind you may want to sand the very tip with some sandpaper just to ensure you don't make a mistake.
7) Once you've removed all the old material, clean it. I used Acetone and wiped it down a number of times, just so I had as clean a surface as possible. If you choose to paint it, you will have one heck of a nicely prepped surface now. (Ignore wifey's legs) Refer to Bay13 for painting suggestions...
Get the Blackout tape out and cut a piece the length of your entire trim piece. Start at the back end (not the windshield end). I peeled 4 to 6 inches of tape at a time, and lined up the outer edge of the trim with my blackout tape, and carefully pressed the outer edge. I DID NOT simply smooth the entire piece out as I went, I allowed that inner edge to stay loose, so that as I progressed, if I found an air bubble or that I'd missed the edge, I could peel the tape up and fix it. Work it to the very end. Then carefully trim the "windshield edge" and work the rubber back around it. 
9) I should add that I used a couple of fresh blades as I worked through the following steps, because as you will see, it's very easy to miss making the following cuts because of a dulled blade. I also had a fingernail to use so if you don't you will want to find a nice small smooth metal edge to use. I suggest possibly a cuticle tool found attached to a nail clipper, for instance. Now start working the inner edge with the blackout tape. I again used my thumb and folded back the rubber, and smoothed out the tape on the top, and around the edge, but trying to be careful of squeezing it onto the rubber, as that will have to be removed. I used my nail and squeezed the tape right under the lip of the metal trim.
10) With that fresh blade, pick an end, then carefully "score" the tape all the way along the inside of that edge. Obviously tricky, huh? Not so bad though. I did nick the rubber in a few places, but not all the way through. I found that if you carefully score it, and then start peeling, the excess comes away very nicely. I then went over that edge a few times with my nail.
11) I spent a little more time smoothing out the tape all over with my thumb, and that... is that. Looks so nice that I have to do the other side now.
I should clarify that I refer to the "outer" edge as being the edge which is closest to the sides of the vehicle, and the "inner" edge is the edge closest to the sunroof side. It took about 2 hours on this first one, but I can see it taking maybe an hour now that I've figured out what to do... Difficult? Nope, basic backyard stuff. Time consuming? Yup, and it pays off. "Pay Attention to Detail" never meant so much to me before.
--> Added... I completed the second one and had to redo the finishing sanding. I found that I had not paid as much attention to the detail of the final prep, and when I started taping, I had some little bumps and lines. I spent ten more minutes sanding with some fine grit sandpaper and then re-taped, and it's very smooth and clean. Think of it as if you were indeed going to paint it and you won't have any trouble.
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