How do I bring this up to my store manager or even my district manager without getting in trouble myself?

The grey shirt I close with is an absolutely worthless manager. Although he has freely given me his password, and I know I shouldn't have it in the first place, I process and generate my own returns by logging in as me first, overriding myself with his password, and processing the second half of the return while being logged in as him. The guy does nothing besides standing around and puffing on his vape. He doesn't help customers out unless he absolutely has to, nor will he answer any phone calls except on rare occasions, and simply lets the phone ring until I put the customer on hold until I can get back to them after I'm finished helping out all of the customers he's ignoring. He also refers all of the commercial customers that come up to him to me. What's also wild is that he's been there far longer with me and will ask me where parts are or have me go pull them altogether. I don't mind doing any of this, but if I'm doing his job besides pulling the deposits and scanning in my returns, I deserve his position and the hours that come along with it. I just don't know how to bring this up to my store manager or possibly my district manager without getting into trouble myself because we're both breaking rules.