It does an ok job at saying what SSAO is and what the respective values do, but it does not say where those settings can be altered, I’ve found the ones under lightmass, but I’m not interested in baked AO.
Select your post process volume(or your camera) and scroll down to Ambient Occlusion in Details panel. Click on the white upside down arrow to see advanced options.
I’m still not sure if AO or not, but even with it switched off in my lightmass I still get a sort of AO looking shadow in corners, that may be another setting I have to change (newbie).