I think it would go like this...

            For years I've been hitting my head on bricks…it's gotten me nowhere. I've spent far too long spiraling down giant tubes into an abyss full of narcotics. There were times when I thought I could shoot fire, times when I thought I was invincible, and times when I thought I was double my actual size. But in the end I'd come back to reality: I'm just some smuck overweight plumber who thinks there's a princess waiting for in some castle. Christ…I haven't even changed my cloths in 22 years. I'd buy new cloths if I could afford it, but my only income is finding random coins that have been thrown on the ground.
            I can't live like this anymore. I'm sorry to break all of your hearts like this, but this life of mine has to end. Luigi, I have nothing to offer for you, but please take care of Yoshi. He tends to run around wildly and destroy things if someone doesn't keep him company. And please take care of our cart. I'll always remember the times we would throw garbage at other cars. It was one of the few times I had a good laugh. Thanks for being a good friend.
            To everyone else, I'm sorry for any pain I've caused you over the years. I know I stepped on some of you and threw others around in a rage fueled by my drug addiction. I want you all to know that no matter how violent I was and no matter what I said, I never meant to really hurt anybody.
            Goodbye. I hope to see you all in the next life.

                                                Love,
                                                   Mario