How do i go in for the kiss first?

im a girl (15) and there's thi guy i like and he likes me, i want to go in and just kiss him first because i know if i don't do it he wont either, how do i do this? how do i get the nerve up to do it! im kinda a chicken but if it comes down to it and i have to ill do it! he's a lot taller so i cant just go in for it lol and ideas?