To initialize, call initOpenVR after initializing the render window and scene manager: OgreOpenVR::initOpenVR(sceneManager, renderWindow);
Then instead of RenderOneFrame(), call OgreOpenVR::update()
Based off of Kojack's Ogre Oculus example:
http://www.ogre3d.org/forums/viewtopic.php?f=5&t=81627&start=100#p525592
And OpenVR's samples: