How can I change the Sony Z Series Walkman?

How can I change the Sony Z Series Walkman?

I get confused with your question. Did you mean, since the Sony Z Series Walkman doesn’t play Google music well, what changes can we make on the player itself? Or you are asking what application can play Google music well? Sony Z is an Android phone without a phone right? Android has made itself as one of the leading nowadays so I'm sure there are lots of Media player available for your Sony Z that can play your music well. And also, when you buy Sony Z, it is pre loaded with a demo copy of Riptide GP on which you can play your music and video smoothly. There is also an application that helps you use DLNA on listening to music and viewing your pictures and videos. The Sony music player is also good.