Just out of curiosity, why'd you buy the mounts w/o knowing how to install them? Not to burn you or anything but were you relying on this forum to help you get them in?
Kills me how so many of the tech threads here are so "hold my handish..."
Here's a tutorial from importnut.net; they're installing Nismo mounts but it'll give you a relative idea of how your install should go.
http://importnut.net/nismomm.htm
Good luck.