So correct me if I got this right you are looking to completely remove the VCSA and then do a reinstall? If this is what you are planning to do, it is important to understand where is the database because modifying the VCSA will lead to scenarios such as :
1) If it's an internal database you will need to migrate this prior to doing anything else you may end up losing data
2) If its an external database and since the clusters, switches etc are from the vCenter you will need to rebuild everything.
For migration of the database, you can refer to Using dbmigrate to migrate from PostgreSQL to MySQL in VMware vFabric Hyperic Server (1030259) | VMw...
One avenue to look at is the built-in VCSA backup tool in 6.5. This will allow you to take a full backup of the settings, configuration and the database elements within the appliance. If you then wish to deploy a fresh one, you then have the ability to restore all of the settings etc back into the new appliance.
Of course, there's other points to consider:
Hope that helps 🙂