Hi. In my experience, it has been a process, not an event. Just for the database, open your trunk and take a real close look at your main hinges on both sides. Is there any paint scraping wear? Is anything bent? Close the hood and watch the operation of the hinges. I say this because I started to adjust my trunk for the same problem you are having and I noticed my hinge was bent way out of whack.
At first, I thought it was just an adjustment. See page two of this post to see some pictures. Rear Deck Hinge Bolt
Why did it get bent? Who knows. I am the second owner. I have the part. It just has to get warm enough here in southern Virginia for me to install it. Anyhow, if the hinges are not up to snuff, all the adjusting in the world will only make your overall condition worse. As much as I love this car (2008 Base Premium) the body panel fitment is worse than any other car I have ever seen, excepting the Original Griswald Family Truck'ster.
If you read the PDF, the instructions are pretty much right on. The pictures are OK, but sometimes the text is a bit off. The movement of things is easy. The problem is you move it to one place, and then someplace else pops up, or down. It can be accomplished; it's just a process. If you would not mind, can you post some pictures of your condition and your work? I am very interested in lining up the body panels, and I prefer to see the real deal daily driver out in someone's backyard, rather than two guys working on a new car in a shop.