First go here and configure your radio and copy your embed code to a text editor.
In a board without Nexus go to your ACP> System Settings> System> Ad Code Integration and enter the code in
the Sidebar Code and put <CENTER></CENTER> tags around it:
and click the "Upgrade Settings" button.
Go to your ACP> Applications & Modules> Manage Hooks section and make sure the Ad Code Sidebar hook is enabled and
drag and drop it to the position you want your radio to appear in the sidebar.
For boards with Nexus installed it's pretty much the same except you need to go to Promotions> Adverts and create an advert
in the sideblock the same way.