What I did (should you choose this method) Is hold the visor exactly where you want it, and then, starting on the main body, the vertical part, I went on the sides with the glue (note: DO NOT GET GLUE ON THE VISOR!!), just have the glue be on the sides and the actual helmet only. After that, I went to the ends of each side of the visor at eye level, and sealed those ends off (some people like to leave it partially open for ventilation) I then proceeded to glue the top rim of the visor, and then finnished off by gluing around the whole visor for a complete seal. I should note that it is quite necessary that you hold it and glue it exactly where you want it, because I leanred the hard way, one mandable was slightly higher then the other. Prying off the dried glue is NOT fun at all. I can say with complete confidence that the hot glue is a VERY, VERy secure method of attachment. Good luck!
-tubachris