What do you mean “release him from the band”? If you release him, THEN THERE IS NO BAND, you silly goose. It would JUST BE YOU.
And you don’t even have the POWER to kick him off, since the band would be 50% his and 50% yours, by definition. That’s about as silly as the democrats saying “ok we are impeaching Trump since 50% of the country, aka us democrats, want him ousted.”
Instead, what you should do with your friend is just make it about yourself not thinking the band is a good idea and say that you, yourself are leaving it. For example “Hey look man, you’re a really good (singer; player; etc) and I love the band thing we’ve got going here but I gotta be honest man, I’ve got bills to pay and as you can see, we’re not really making any money or progress with the band. so I’ve gotta focus on work and stuff. I’m still down for us to hang as friends a lot, and I hope we do, but the band thing is just seeming like a waste of time IMO, as fun as it was.”
TL;DR = don’t say some stupid unnecessary sh^t like saying you’re kicking him out of the band. You don’t even have the authority to say that, since it’s only you 2 to begin with, and it’ll just create unnecessary annoyance and drama. Instead just say you’re stepping away from it bcuz of financial reasons and needing the bills paid. You can also throw in something like “these fans don’t recognize our talent, bro. They should but they don’t”. Make it seem like you see him as still being your friend and part of your team. Just make the band itself seem like a waste of time. Don’t say you’re kicking him out. Why would that be necessary to phrase it in that way?