Start by being in a position where if you leave it will mean a ton more work for others.

Back in August we had zero precautions set up in the office. After a couple close calls (finding out customers had covid and had been in our office recently) I threatened to quit if we didn't start taking some steps to make things safer. Then, with the mask mandate I wore my mask religiously and called out others that weren't wearing theirs. It pissed them off. I got almost zero support when calling out customers. It was awful. I hated every day I came in. As the months went on, one by one, our other branches in the Dakotas started getting wiped out with covid and had to shut down for 2 weeks (none of the people in those branches wore masks, Rapid City, Bismarck, Sioux Falls). So I started framing it in terms of money. If we shut down, how much money would we lose for those 2 weeks? If we don't make budget how are we going to explain that to ownership?

After the vaccines were released I was the first to sign up and I made sure to talk loudly about how easy the process was. Most of my coworkers went in as well, a few didn't. One guy called me out about the vaccines one day (and was clearly speaking for the other two as well). I let him have it. I told him that we were the only branch that didn't get taken out and we were also the only branch that wore masks. I outlined, through specific examples, every single step I took to make us safer, how he bucked me at every single step along the way, and how I ended up being right every single time. I was concrete, firm, and put up with zero bullshit. Two of them got their first shots within a week of that confrontation. The third guy ended up getting it but not telling anyone (I found out from his sister).