Topic: Convert wmv to mpeg1

[spyder9]

I need recommendations.  I'm working on a project for my boss.  She wants to edit out some swear words on a wmv video.  What would you recommend for converting the wmv to mpeg1?  Freeware suggestions?

Here's what I want to do:

1) Convert wmv to mpeg1
2) Separate the audio from the video
3) Insert blanks over the swear words
4) Sew the video and audio back together
5) Convert back to wmv.

Your input would be greatly appreciated.  I never worked with wmv before, because of its inferiority.