Those are tricky for me too, and it's hard to get it perfect. You have to be patient and work slowly. First use the right glue; Cyanoacrylate which is most instant glues like krazyglue. I prefer this loctite because of the fine nozzle which is convenient for application in tight spaces.

Measure the wide rail and cut to length. Position on the blade edge. Put one small drop of glue under the rail at each end on each side of the blade. Now you'll have the rail steady in the right position. Start on one side of the blade lifting the rubber and applying glue in 3-4" sections. Apply very little glue, I put down a row of drops rather than a continuous line. Have a paper towel ready. Push the rubber down with a finger and slide the finger along the section being glued. This will squeeze out excess glue, wipe it down with the paper towel in a quick motion alongside the rail, otherwise the paper will get glued to the blade. The moment excess glue is removed the rubber will bond to the blade. Keep working section by section until you finish one side, then do the next.
As you can see there's no trick to it, it's just tedious, and doesn't come out perfect. But it will hold. Instant glue is temperamental and you have to develop a feel for it, this comes after gluing a few blades. I have a better/faster system for the small tendon rails, they're easier to work with.
I'd love to find out how to glue water channeling rails on in a more efficient manner. I'm willing to reward someone who provides me this information with gear. These are the rails we're talking about.
