How Do I Do It?
It's simple. If you're LGBT, you just talk about your life with three straight people you are close to. That's really it. Tell them about your relationships. Tell them about growing up. Tell them about how you've felt different from them and how you've felt the same. Tell them about the struggles you've had because of your sexual orientation or gender identity and the ways you overcame them (especially if you had help from straight allies). Tell them how being L, G, B or T has made your life uniquely yours.
If you're straight, talk to people about how being LGBT has affected the lives of your friends, and what that has meant to you. Tell them that you're sick and tired of hearing how your gay friends' lives are being made more difficult. Tell them you won't put up with it when people make homophobic or transphobic comments. Tell them that everyone deserves respect.
The most important thing is to have the conversations. We've got some suggestions of how you can get the conversation rolling. We've also got more in-depth suggestions
of what you could talk about
(and a few things that maybe you should stay away from). You can get more help with having your conversations here