Question Restore/migrate to new server for test enviorment

Hi

What is the easiest/fastest way to restore our running zxbackup to a new server ? New server is same OS, and contains a fresh zimbra install (8.6).
The goal is to "simulate" upgradring from 8.6 to 8.7. , if everthing goes smoothly we can do the upgrade on the production server. Currently running zextras version 2.2.4 on the production server.

Dont really need to restore all accounts etc, just server settings , and some test accounts.

I have read some "guides" on your wikie on the topic, but it gets confusing