This addon can be installed like any other marketplace item.
Before you van use this addon, make sure your authentication methodes in concrete5 are setup correctly.
This addon uses the core authentication types to enable your site visitor to login.
The page used for this is located here: <yoursite>/index.php/dashboard/system/registration/authentication
Or go to dashboard -> system & settings -> authentication types
1) When adding the block choose the login title (you can use this in your custom template, but is not used by default).
2) Choose if you want an ajax type of login.
3) Do you want to this addon to redirect your visitor after login, then you can select the redirect page, or add the page by hand here.
4) By default Login Block Pro uses all enabled authentication types, and let's the user select it's desired way to login. Here you can force the addon to use this authentication type. You can only choose enabled types.
Login Block Pro comes with a tabbed custom template as a bonus.
If you want to create a custom template to change the layout of the login forms, then you should change your global login template as well. You can however add css to intergate the login with your site.