The persona implies that when he dies, he wants the person (or persons) he loved will never resent him for his mistakes, his wrongdoings.
He wants them to remember all the good things about him and forget the rest, the bad ones.
He knows he is not perfect but neither anybody else, so he's asking to remembered despite his flaws.
He doesn't give a damn about what other people think of him, what matters is what loved ones think about him after he dies.
"leave out all the rest" means forget the bad memories, ignore other people's bad talks about the deceased.
And he also wants to say that he is sorry. "i cant be who u r"