The WP-Backend is secured by an IP Blocker.
Upload the plugin into the plugin folder and activate it in the WP-Backend.
Goto the Manage->Adminprotection panel and enter one or more IPs (note: 1 IP per line), Bellow you can see if your current IP would be accepted or not. Then activate the protection checkbox
For Backwards compability please deactivate and reactivate the Plugin!