Google Play Store for ASUS Zenfone 2 - ZE551ML

Hi, I've seen some posts on how to add Google Play Store on my chinese version of the Zenfone 2. However, can some one please walk step by step on how to do it? All I saw was "Transfer it to the phone and enable unknown sources...Install apk normally.." - but - I don't know where it needs to go and how to install it? The file I received was "com.forfun.ericxiang-1.apk" Thank you