Samsung Moment :: Stock Messaging (Group Texting)

I have the contacts set up in my starred groups already but can't figure out how to text the contacts in a specific group (e.g. Family, CoWorkers, Friends) from my stock messenger. I can do it using the handcent app and although I have the notification setting off on the stock messenger the message still makes its way to the stock messenger and handcent which I believe would take up twice as much memory on my phone causing it to lagg. if I am wrong in assuming this and what I can do to fix this whether it be the correct way in sending a message to a group or deleting the stock messaging app, etc...