Just copy all files from the .rar file into your Skyrim install folder.
-> SteamApps\common\Skyrim
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My personal SweetFX config i use for Screenshots.
You may have to tune down sharpening, depending on your resolution.
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�Update 1.1
A more filmic look. More Red, wider bloom and a bit more color as well.
�Update 1.2
Made it a bit Sharper.
�Update 1.3
Small update to DPX ( A bit less color ) and the Bloom.
Now uses FXAA. Works better than SMAA in this game.
�Update 1.4 (29.6.2013)
Final version of my Skyrim preset.
I'm not sure anymore what changed but it wasn't much.
I added some contrast and some kind of filmic effect to dark areas though.
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FXAA (SMAA works too, but not as good as FXAA)
TVLEVELS
LUMASHARPEN
GAUSSIAN (Bloom)
FILMGRAIN (You can turn it off if you want to.)
DPX
LIFTGAMMAGAIN
VIBRANCE
CURVES
DITHER

SweetFX doesn't need a High End PC.
It maybe costs 4-6fps in performance.

After that, just start the game and enable/disable the shader with the "Insert" key above the arrowkeys.
If you want to take some screenshots with those shaders use the "End->" key above the arrowkeys.