Besides importing the application, you'll need to :
- setup an oauth_consumer.properties file, as specified here
- set the authclass parameter (xwiki.authentication.authclass) to "org.xwiki.social.authentication.internal.SocialAuthServiceImpl" in xwiki.cfg
- if you want a global setup on a XEM (only global users, set xwiki.authentication.socialLogin.globalConfiguration to "1" also in xwiki.cfg
- copy the login.vm file in src/main/webapp to your wiki skin
- add XWiki.SocialLoginTranslations to your wiki i18n documents bundle
- visit your wiki administration "social auth" section to configure more settings