High ISO low noise tutorial [updated]

Update 1.1:

• Added what is now step 1
• Added further explanations in some places
• Added green highlights to make text more readable

This took a hell of a long time to put together and with Corel Draw crashing on me on more than one occasion I'm seriously surprised I even made it this far.

At any rate, I wish you enjoy this tutorial a lot more than I enjoyed making it.

You may repost this tutorial or modify it as long as you credit me and share it forward.

If you have questions or requests please leave them in the comments.

P.S. Yes, that is the new PS - I'm trying it out.

Final Update, must read
The tutorial is old and I can't find the original file and I'm waaaaaaaaaaaaay too lazy to remake it so here it is a last update:
The ratios for the layer opacity are actually wrong. It's 100 - (100 / layer number). So for example for the first layer after the 100% opacity one you have 100 - (100 / 2) = 50% transparency. For the next, 33%, for the next, 25% and so on.

But an easier way to do this is to load all of the layers as a smart object and set the stacking mode of the object to mean (or median if that suits your tastes more). The result should be more or less the same.