A number of ways you could - I am really cautious with installing a new template so I would create a new site version - becomes more problematic if the site is large or the server poor
https://www.akeebabackup.com/videos/1212-akeeba-backup-core/1619-abtc05-site-transfer-wizard.html
I have encountered problems with servers on occasion so I mostly use Akeeba backup to backup, manually download and the manually upload
Creating a new development site avoids the risk of breaking a site