You could perform a Migration rather than building a new server from scratch. With this method you restore the database and content from the original server onto the new server. An overview of the process is available at https://help.hcltechsw.com/bigfix/10.0/platform/Platform/Config/t_mgrt_rootapp_server.html
You’ll need to install the same version of BigFix as is running now. If you also want to upgrade the platform, I’d suggest performing the migration first, testing that it has been successful, and then performing the upgrade after.
After the migration, you may either set up a DNS Alias redirecting the original platform hostname to the new server, or use the BESAdmin Tool to configure the “Last Fallback Relay” option to point to the new Root Server (or a Relay connecting to the new Root Server).