Downmixing surround to mono - how to assign surround bus output to stereo bus?

Im trying to downmix a 5.1 project to mono. Sonar X1 help file shows how to downmix to stereo in this page -
Surround Mixing (Producer and Studio only) / Configuring SONAR for surround mixing / Downmixing

It says -If you do not have a stereo bus in your project, create one by right-clicking in the Bus pane in the Track view or Console view and selecting Insert Stereo Bus from the menu that appears
.In each of the surround buses, assign the output to a stereo bus.

Can someone explain how to do the last step i.e. assign surround bus output to a stereo bus? I am unable to do it, Ive tried left/right clicking the surround bus everywhere to find the output assign feature.

If you set your Track View filter to "All" or "I/O", you should see the "Output To" widget in the surround bus header. Click the down arrow on the widget and select your stereo bus.

Regards,
Don