All you need is lennys mod loader it can be downloade here https://www.rdr2mods.com/downloads/rdr2/tools/76-lennys-mod-loader-rdr/
(there's an installation vid here https://www.youtube.com/watch?v=E-OIFFcIKDs&t=258s&ab_channel=G17Media )
You also need alexander blades scripthook here http://www.dev-c.com/rdr2/scripthookrdr2/ when you've downlaoded the scripthook just put it inro rdr2 directory aka where you have your game installed.
now go into lml folder and make a folder called stream.
After that just put the files from my mod into the stream folder you just created.