Your friend is right on something: there are a lot of rules in the Catholic Church. However, these should be burdens we bear willingly. After all, we hear every Sunday in the Mass how Christ was condemned to death, a death he freely accepted. If we can bear a few things that are far less painful than being crucified, we come to know God better and become closer to him and are more able to show him to others. This is what I get out of the Catholic Church. A man that I have never met (yet, I ironically meet him every Sunday in the Eucharist) would suffer and die for me and the rest of the faithful–his people. I have been Catholic all my life and have never seen anything that compares to the beauty and majesty of the Church.
Try to show your friend just how beautiful the Church is. Try to show your friend how the benefits are far greater than avoiding what we are directed to do by the Church. If you first embrace the beauty of all the Church is, then the burdens become lighter. This is similar to what is taught in Scouting–put your own wants and needs aside in favor of the far greater thing…serving your fellow man. In this case, we are serving God.
I will pray for your friend, and you should as well.