How to edit videos using IMovie on you iPhone/iPod?

Well this might sound pretty pathetic, but I can't firgure out how to use iMovie on my iPod. I'm trying to make makeup tutorials (the picture quality is actually really good surprisingly) and I can't figure out how to take pieces out that I don't need. For example later on in the movie, I do my mascara, and I take about 5 minutes on my mascara but I only want I show about 5 seconds of it in the video. So I tried splitting it, it worked but it didn't let me split anything else in the video. Same goes for the trimming. I don't know it's getting me real angry. I also tried filming it with my video camera but I can't figure out how to use windows movie maker either. It seems to only let me take of stuff that at the very beginning or very end of the video. Any advice would be helpful!

I like Final Cut Pro