OK, so there are several ways of approaching this task. Follow the ROM procedure or follow the procedure outlined below:

In typical German engineering to English translation lost, the ROM essentially gives you two sets of directions, distinctly little on the seal itself, and far more on the removal of the seal retainers, which is unrelated to the seal replacement itself.

You may be left thinking that the seal replacement procedure is akin to: "secure seal in place, disassemble vehicle, replace seal with new and afix in place, reassemble vehicle around new seal"

The alternative procedure is:
1. Open Sunroof
2. Remove seal by pulling straight (laterally) into the sunroof void starting in the middle and working your way all around until completely removed
3. Clean channel (I used a rag folded over a Popsicle stick with cleaner) all around
4. Serrated Channel Side Up. Starting at the rearmost section where the shorter "U" of the seal (facing rear) is bonded to the longer "U" (retainer #5 per ROM) Insert new seal pressing in (laterally) until fully seated and work your way all the way around until fully installed.

In reality the job should take 15-20 min tops. It is the easiest sunroof seal replacement process I've ever encountered. There may be more involved upon closing the sunroof all the way against the new seal, but I'll note anything I observe when I get there.

In my case, I'm currently addressing some rust spots before I finally install the new seal. I did carefully remove the old seal and noted that it is pressure fitted, and reinstalled it several times to get the feel for it.

The seal rides in the channel that requires it to be fully pressed in and seated within the channel. Worth noting that the side with the serrated seal faces upward and the location of the two bonded joints and where they fit between channels #5 and channels #3,4

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Stable Mates:
1987 300TD 310K mi (Hans)
2008 Jeep Grand Cherokee OM642 165k mi (Benzrokee)