My 2 cents worth is that you should use epoxy. When I replaced the HD in my 2008 non-unibody MBP, I injured some plastic and aluminum clips that hold the computer together. Cyanoacrylate glue ...

What kind of glue should I get to do the job? I dont want the fans to fall off and I want it to dry decently fast. Thanks.

Lastly, keep in mind that if you plan to use E6000 on outdoor projects, there's a special type for that called E6800 — it's UV resistant, so it won't yellow or crack in the sun.