This shader comes with OpenMW, there's no need to install anything extra for it.
Shaders are enabled and configured with the
F2 key while in game. I've had good results with loading this after the
hdr shaders (from OMWFX Shaders).
If you're following a mod list, your shader chain in the
settings.cfg file might look like this (with this load order):
chain = ssao_hq,underwater_interior_effects,underwater_effects,clouds,godrays,bloomlinear,wetworld,SSR,hdr,fxaa
OpenMW 0.48 or newer is required!