I keep forgetting how to upgrade Docker containers because I use them so infrequently.

Here are simple commands to upgrade the (very slick) nginx-proxy-manager container.

# Go into the directory with the .yaml file
cd ~/nginx-proxy-manager

# Stop the container
sudo docker-compose stop

# Pull the latest container
sudo docker-compose pull
# OR
# sudo docker pull jc21/nginx-proxy-manager

# Start the container again (-d for detached)
sudo docker-compose up -d

Looks like just doing docker-compose pull will stop the containers, so even the docker-compose stop might not be necessary.

Update: I found the page that gives the same instructions.