A couple of options.
1. Copy the module to the production environment while the MOM is down, create a new subfolder in <EMHOME>/config/modules/FuseESBV8Prod, edit the domains.xml, and add your new domain. Restart your MOM, open MM Editor and update anything you want to say "Prod" (including the module name).
2. While in your pre-production environment, from the MM Editor, copy the current module and give it a new production name. Make any edits you want for production use and save. Go onto your MOM and take a copy of the JAR file and follow the same deployment directions as option #1.
You can also hotdeploy MM by copying the MM JAR file to <EMHOME>/deploy. By default, the EM is configured to look for new modules in this directory every 60 seconds. When the EM notices a new module to deploy, you could see some slowness in your workstation response as it moves the JAR to the ./config/modules directory.
As a reminder, any domain changes will require a restart of all EMS in a cluster and you will need to copy the domains.xml from MOM to Collectors.