Hi.
Redmine backups are realized according database engine used, so we need to know firts what database engine are you using? postgresql? sqlite? mysql?
Other point is because we need ssh access to your system for run appropiate commands.
We will be delivering a you an report with all our job (you can see previous recommendations on our profile).
Even, we can provide you with our service for install new redmine instance in your new server.
Open to questions,