Exactly the same things! There's no too late with a virus, the same things work to treat it no matter what the infection counts are.
Stay home. If you can't stay home, wear a mask and stay outside. Don't travel. Get tested regularly if you can't meet these rules. Follow the instructions of the scientists we've all been ignoring. Vote for people who will (or against those who won't).
Your argument seems to be of the form "Well, we fucked up, but it's too late now so we might as well open up." That's just not true. We can still fix this and save tens or hundreds of thousands of lives.
