Hello @RWA,
So far as I know there is not one specific resource that can assist with this, but here are some resources that may help with various aspects of this process:
https://docs.pkp.sfu.ca/journal-policies-workflows/en/journal-ceases
https://ojs-services.com/ojs-installation-and-settings/moving-ojs-to-a-different-server/
https://docs.pkp.sfu.ca/admin-guide/en/deploy-multi-tenant (if you are in a multi-tenant situation)
By the way, version 3.1 is quite outdated, and unsupported, I highly recommend upgrading as soon as you’re able to.
-Roger
PKP Team