Extract the two archives (location does not matter)
Run the 3.1 EXE
Run the 3.1 patch EXE
Create a folder "Streamline-10400" in the Bash Installers folder
Create two folders inside of it: "Core" and "Debug".
Go to the Data folder.
Select the folder "Streamline", Streamline.esp and the Streamline docs (a .MHT file and a few .TXT file in the Docs folder.)
Move them to the "Streamline-10400\Core" folder in the Bash Installers folder
In "Streamline-10400\Core\Streamline\ESPs" folder, copy the debug version of Streamline.esp.
Place the copy in the Debug folder at the top level of the package, and delete that ESPs subfolder in the Core subpackage.
Select all of the contents of Streamline-10400, right-click and (7-zip) add them to "Streamline-10400.7z.">> notes: 1) when you select multiple items, 7-zip's add to ".7z" is the folder's name 2) if this new archive shares the exact same name as the old archive, when you place it in the Bash Installers folder and overwrite the old archive, you will not have to reposition it in BAIN.
Move newly created archive up into Bash Installers folder.
Delete the leftover "Streamline-10400" folder, the EXEs and the old SL archives