add upgrade instructions

Author: pdurbin

doc/release-notes/6.10-release-notes.md

@@ -177,3 +177,25 @@ If this is a new installation, please follow our [Installation Guide](https://gu
 Once you are in production, we would be delighted to update our [map of Dataverse installations around the world](https://dataverse.org/installations) to include yours! Please [create an issue](https://github.com/IQSS/dataverse-installations/issues) or email us at support@dataverse.org to join the club!
 
 You are also very welcome to join the [Global Dataverse Community Consortium](https://www.gdcc.io/) (GDCC).
+
+## Upgrade Instructions
+
+Upgrading requires a maintenance window and downtime. Please plan accordingly, create backups of your database, etc.
+
+Note: These instructions assume that you are upgrading from the immediate previous version. That is to say, you've already upgraded through all the 6.x releases and are now running Dataverse 6.9. See [tags on GitHub](https://github.com/IQSS/dataverse/tags) for a list of versions. If you are running an earlier version, the only supported way to upgrade is to progress through the upgrades to all the releases in between before attempting the upgrade to this version.
+
+If you are running Payara as a non-root user (and you should be!), **remember not to execute the commands below as root**. By default, Payara runs as the `dataverse` user. In the commands below, we use sudo to run the commands as a non-root user.
+
+Also, we assume that Payara 6 is installed in `/usr/local/payara6`. If not, adjust as needed.
+
+1. Undeploy Dataverse, using the unprivileged service account ("dataverse", by default).
+
+   `sudo -u dataverse /usr/local/payara6/bin/asadmin list-applications`
+
+   `sudo -u dataverse /usr/local/payara6/bin/asadmin undeploy dataverse-6.9`
+
+1. Deploy the Dataverse 6.10 war file.
+
+   `wget https://github.com/IQSS/dataverse/releases/download/v6.10/dataverse-6.10.war`
+
+   `sudo -u dataverse /usr/local/payara7/bin/asadmin deploy dataverse-6.10.war`