How to change the file size of a movie?

I have a .wmv that is 37.7 MB and it needs to be 30 MB. How can I make it smaller?



I have iMovie and final cut pro.How to change the file size of a movie?
well it is best not to use .wmv format because they normally take up a lot of space try www.mediaconverter.org and change it that way .mp4 is normally a small but good file format to aim for.