In a Xamarin.android project, How can I remove warnings: duplicate zip entry [classes.jar…]

I am getting errors:

         Warning can't write resource [META-INF/MANIFEST.MF] (Duplicate zip entry [classes.jar:META-INF/MANIFEST.MF])   ColorPoint.Xamarin.XAndroid C:\Projects\cpxm\Product\Production\ColorPoint.Xamarin.Android\PROGUARD 

         Warning can't write resource [META-INF/MANIFEST.MF] (Duplicate zip entry [internal_impl-22.2.1.jar:META-INF/MANIFEST.MF])  ColorPoint.Xamarin.XAndroid C:\Projects\cpxm\Product\Production\ColorPoint.Xamarin.Android\PROGUARD

I deleted the 'classes.jar' and 'internal_impl-22.2.1.jar' files completely but still same warnings. When I try to edit the files - like some answers have said, the file is encoded and impossible to find duplicates in notepad ++

project still builds fine, just the two warnings, and seems like proguard is not shrinking my app size by much.

also there is no folder at : C:\Projects\cpxm\Product\Production\ColorPoint.Xamarin.Android\PROGUARD..... this is where duplicate is supposed to be

there is proguard .cfg files at: C:\Projects\cpxm\Product\Production\ColorPoint.Xamarin.Android\obj\release\PROGU‌​ARD but cant edit them as they encoded

I am not using build.gradle and not sure what it is. A lot of answers say to add code to packaging options in build.gradle.. Not sure how that would be done