I deleted your thread because we just had a thread asking the very same question. No big deal or anything since that thread is now on the second page. I just don't want people to think that starting a thread here is the ideal way to meet Weezer as it will make this place very tiresome to read through.
I'm afraid there's no easy way to get a backstage pass. A lot of it has to do with who you know in relation to the band, their management, etc.
I know that's not a super helpful answer but it's the only one you're really gonna find. Good luck and have fun at those shows. Good job bringing up three Weezer fans! =w=