Before installing the mods, a few other thing need to be installed
1 - If you haven't already, sign up at the Nexus. (LINK)
It's free, and it takes 2 minutes. The Nexus is a great site for mods in general, so it's definitely worth the time.
2 - Download and install the NexusModManager (NMM) (LINK) *Install descriptions are found at the Nexus page if needed.
Download and install
"Skyrim Script Extender".
If you have the Steam version, download from the Steam workshop instead: (LINK)
If you have the another digital version or the DVD version, then download from the SKSE website: (LINK)
*You can either download SKSE in a .7z package or as an installer. If you choose the package, just unpack the files into the root of the Skyrim game folder. Now make a shortcut to "skse_loader.exe", and use this shortcut to launch Skyrim from now on.
4 - Download and install TES5Edit. (LINK)
Unpack and copy the files to any directory, then make a shortcut to "TES5Edit.exe".
This tool is used to clean up Bethesda's "lazy edits" from their DLCs. See description in the Cleaning section. (LINK)
5 - Download "TES 5 ESS Files Editor". (LINK)
Download the latest version and unpack the files to any directory. Make a shortcut to "TESVESSE.exe".
*If you plan to start a new game after SBP installation, this file is not absolutely necessary, but I still recommend it. If you want to continue a saved game, you definitely need this tool. It's used to remove old script data from a save-game file. Unfortunately Skyrim stores scripts in the save-game files, so if you remove a mod which contains scripts, then the scripts stay in the save-game, and can cause all kinds of errors.
6 - Find out how much video memory you have on your graphics card.
If you are not sure, use this tool made by Boris Vorontsov. (LINK)
7 - Make some coffee and get ready for several hours of downloading and installing. At the end you will get the result of months of tweaking and testing.
Curious if the results are worth the effort? - Here are some before/after screenshots.
*I didn't have any screenshots from before installing everything, so I found some screenshots using Google instead. Then I tried taking some as-similar-as-possible screenshot with the SBP ENB settings enabled and all mods loaded.
S.B.P. ENB 3.14 Screenshots
S.B.P. ENB 2.54 Screenshots