So first of... download it, make sure its downloaded as a "zip" (im using firfox but its the same for all browsers)
By default it should save to your downloads folder, if not you changed it and should know
Then open it with winrar or 7zip, i reccomend winrar, if you have 7zip, delete it...
Highlight the 3 folders and click and drag them into your .minecraft destination, or if you have the portable version just put it that folder.
If it asks you to merge, replace, or keep both but rename, just click either merge or replace so the files combine.
Then after youre done moving the files run your launcher and select the "1.7.2-Forge10.12.2.1127" version, it might take a bit longer to load since it has alot of mods.
And thats the end of the installation... johnny.
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