Maximage Background Slider uses the upgrade install method, so you can install over the top of previous versions.
Do not uninstall Maximage Background Slider prior to upgrading, as you will loose all your settings.
It is always a good idea to do a full site backup prior to installing any new software versions. I recommend using Akeeba Backup.
Best practice is to install any new software on a development copy of your site, and fully test prior to upgrading the live site.