Hey I just got SPM 5 working I will tell you steps I took, ignore my previous posts as those errors have not occurred this time around.
First download the google drive http://pmdownloads.weebly.com/
1. Install Legendary Edition Skyrim on Steam, untick/disable the High Res Texture Pack like this: https://i.imgur.com/OeXBDiT.png once you begin the install.
Make sure this location has enough space ~200 GB as it will be used for everything.
Also I opened my Skyrim, once installed, and set windowed mode as well as putting maximum graphics, I am unsure if this is necessary because it is probably overridden.
Look at this guide and make your nvidia settings as shown, I did it for TESV.exe and SkyrimLauncher.exe to be sure.
3. Create a X: drive (make it like 50 MB in size) Tutorial: https://www.youtube.com/watch?v=_HgjasKuOBw
4. Don't create any folders in your X: drive, instead do what user tommysparks has said:
open command prompt as administrator and enter the following
mklink /D "X:\Skyrim" "C:\Program Files (x86)\Steam\steamapps\common\Skyrim"
" end quote
I am unsure what the purpose of X: drive is, I can only say I did this and everything worked out in the end.
5. Begin slow process of moving the downloaded files directly into Skyrim directory. I had some errors pop up and I ignored them all, unsure if important.
6. Step 4 of the steam install guide has some errors so do not follow it blindly, do this instead: (this step may not be necessary since we created the X: drive)
Step 4: Open File "Modorganizer.ini" in your Skyrim Folder using Notepad++ https://notepad-plus-plus.org/
Press CTRL+H for Notepad and Notepad++ to bring up the Find & Replace Window
On the left hand side of the window, only tick the last box (Wrap around) and use Search mode 'Normal'
Make sure to edit 'YOUR INSTALL DRIVE LOCATION' to include either \\ or /
Find "X:\\" and Replace with "YOUR INSTALL DRIVE LOCATION\\SteamLibrary\\steamapps\\common\\" and click Replace All
Find "X:/" and Replace with "YOUR INSTALL DRIVE LOCATION/SteamLibrary/steamapps/common/" and click Replace All, e.g. D:/Installed Programs/Steam/steamapps/common/
7. Run ModOrganzier.exe which is included now in your Skyrim directory, don't use your own Mod Organizer.
8. If you are not running 4k monitor, then you must change resolution by editting skyrimprefs.ini e.g. from height 1440 to 1080 and width 2160 to 1920. skyrimprefs.ini found here https://i.imgur.com/cvw7VGX.png
or in X:Skyrim/profiles/RottenDub folder
9. Run Skyrim through Mod Organizer's SKSE (or 'Skyrim Perfectly Modded')
10. Mod Organizer will close and Skyrim will load (takes a minute or so)
Play save 006 for survival or 004 for non-survival (like eating food and sleeping and freezing)
001 is for uncustomised but slightly tweaked settings, I think. More info here by the maker https://www.youtube.com/watch?v=hy1tOZUAWYs
I will comment back if I encounter any issues! Good luck. I hope this guide is in full, however I don't know anything about different operating systems or drivers. I also don't know anything about modding! :P