we as girls can be very emotional, especially if we really trust you. you should definitely avoid texts, emails, and phone calls. if you can't tell her face to face, you don't deserve to be let off the hook about it that easily, period.
let her know how special she is and was to you, if she feels unloved she might be more upset. you could try pulling the friends card, personally i like to stay friends with my exes, but she may not share the same outlook as i do. so, i recommend that you NOT try to kiss her after you break up with her, that's not the best idea. a hug might be okay, but i wouldn't know whether or not she'd accept it. if she asks you questions about why, ANSWER THEM. untied ends never turn out pretty, and she will end up feeling hurt, betrayed, used, and bitter. if she's the jealous type, unresolved problems may reflect on your future girlfriends as well.