How to programatically change view orientation

We need our android app to support Android V2.3 through to V5. We are rendering a Surface view inside a LinearLayout. Our Activity is locked to portrait.

We would like to programatically rotate the LinearLayout view with the same effect as though it changed from Portrait to Landscape. THis whilst keeping other views the same, this is why we need to fix the Activity orienation. Anyone know how to go about this

Thanks