Upgraded from SQL Server 2008 R2 Express to SQL Server 2014

Question

I've upgraded my SQL Server from the 2008 R2 Express edition to a full standard version of SQL Server 2014. Now I'm running them both side by side. But my problem is how can I abandon the 2008 version and only run on the 2014 version? I've check the properties on the SQL Server 2014, and it shows that I'm still with 2008 R2 Express edition. How is that possible?