i cant uninstall Windows Media Player

i recently installed Windows Media Player but then i decided that i prefer VLC Media Player. I wanted to send Windows MP to the trash and empty it but it wont because it says that certain files are locked. How do i uninstall it?

if you want to delete locked files, take them out of trash, get info and then uncheck the box "locked".
if finder tells you that you cannot delete something because its in use by something, just log out/in and then empty trash.
you can also open activity monitor, choose "my processes" and quit the one you think gives a trouble. it can be dangerous to quit system processes so if you are not sure which is which do not do this.

thanks. there were a lot of files locked. i appreciate the help.