Extract the archive to <Polarion Installation>/polarion/plugins.
The configuration is done in <Polarion Installation>/polarion/plugins/com.polarion.alm.minimalinterface_<version>/webapp/WEB-INF/config.properties.
The file contains comments that describe how the configuration works.
In the default configuration there are two "minimal interfaces" configured:
<Polarion Server>/polarion/minimal/internal and <Polarion Server>/polarion/minimal/customer/xyz.
Both create Work Items in project elibrary, if you don't have that project you either have to create it or adjust the target project in the configuration.
The internal interface uses admin - admin to log in, the customer/xyz rProject - rp. If you don't have these users or they have different passwords you have to either create them or adjust the configuration.