Changing the language of a plugin

Hi, I’ve changed the language of my wordpress site, but I’m using a 3rd party plugin that is still in English. This plugin (sidebar-login) has my language’s .mo language file in its /langs folder, but I am not sure how to activate it.
I’ve tried putting the .mo file in the wordpress /languages folder and also in the theme’s /languages folder, but the plugin still remains in English. There is no place to change the language in the plugin’s settings either.

How do I do this?

Nothing need to do . It will auto use the languages of your wordpress. There must be someting wrong with your install .