How to add a long video on to YouTube?

I have a song, like a mega mix, that i want to add to YouTube, it's 1:46:33 long, and i have made it with Windows Movie Maker buy adding the same photo again & again to add up to the length of the song. When i try add it to YouTube from WMM, it say it's too long & that i could try break it up into 15min videos, which what i'm trying to do, how to i break the video up, i don't know how to because i don't know how to break the song up into 15min videos. Anybody know how to?