In order to edit SSRS reports in Visual Studio, you will need SQL Server Data Tools installed. First, go to the Microsoft Download website and find the link to your Visual Studio version. For example, for Visual Studio 2012, go to:
Once downloaded, install the application:
Now, when you open Visual Studio, you will see new Business Intelligence options:
Create a new Report Server project. Right click Reports and add an existing item. Select an existing RDL file to add it to the project. Double click it to open it.
You will now be able to see and edit the report in Visual Studio.