Hi,
as a general workflow, a traditional backup and restore of your bitstreams and database will work fine.
1. fresh install of the last DSpace version into the new VM
2. backup source DSpace:
2.a. pg_dump for the database
2.b. full backup of your [dspace]/assetsstore folder
3. restore that content into the new DSpace
3.a. migrate the database using [dspace]/bin/dspace command [1]
3.b. create a new [dspace]/assetsstore folder into your new instance
Eventually, depending on your actual settings and deployed installation, you should be considering local customizations, migrating statistics, user interface, deployed webapps, etc.
Good luck!
Gonzalo