Installing Reporting Services for an Existing Instance
Install Reporting Services native mode report server
Put the SQL disc into the CDROm drive or run the setup.exe from an SQL ISO file
To install SSRS launch the setup.exe on the installation media, click on Installation in the navigation pane and then click on New SQL Server stand-alone installation or add features to an existing installation:
The Product Key will be filled in, click Next
Accept the terms and click Next
Click Next to install Microsoft Updates or just next with no Updates
Select SQL Server Feature Installation and click Next
In the list of features, mark Reporting Services – Native and then click Next
Like SQL Server itself I am installing an instance named Amicus
Click Install only (Not Install and Configure) and then Next
Select Install to start the installation
Finish the Installation.
Configure Reporting services using this link.