26 steps does seem like a lot, and the note at the bottom really needs to be the first thing, and also really isn't accurate; no reason to move or rotate your model, that can create all kinds of headaches with other scenes you have or if used as a component elsewhere, not to mention shadows).
Here is my short version:
step 1: set the origin in your model at the same point that you plan to use as the origin in the photo. Blue will be up, but make a note of which axis is red and which is green (although you can fix this later if you get it wrong).
step 2: setup MatchPhoto scene like you always do.
step 3: one extra calibration setup is to adjust the scale to match your pre-existing model. I like to have the model transparent to do this.
Notes
1: (watermark note) if your background photo doesn't have any good reference geometry for MatchPhoto then watermark is a good option. Something to be careful about with watermarks (when stretched to fill window) is that you want to keep the aspect ratio of the source image more narrow than what you will ever use for your SketchUp window or exported image. The watermark will keep aspect ratio and scale based on sides or top and bottom (whichever it is snapped to based on aspect ratio). The model however will only scale based on the vertical size of your window. This means if you don't see your a gutter at the sides then your model will move in relation to your watermark. I have attached a quick demo of this. When you have gutter on sides circle fits in square, when you have gutter on top and bottom edge the the circle (which is modeled object) get bigger relative to the blue square on white background (which is jpg screen capture)
2: (my cool post on how to un-crop a photo even if you don't know how it was cropped) I thought this was cool, but didn't get much interest. I'm hoping SU programers are adding this ability to SU7 as we speak 
http://www.sketchucation.com/forums/scf/viewtopic.php?f=15&t=10895
watermarkdemo.skp