Make sure you have already installed Lenny's Mod Loader﻿ and ScripthookRDR2﻿ before installing this mod:

Lenny's Mod Loader: https://www.rdr2mods.com/downloads/rdr2/tools/76-lennys-mod-loader-rdr/

ScriptHookRDR2: http://dev-c.com/rdr2/scripthookrdr2/

Once everything is installed, simply drag the "Model Fixes" folder inside of your "lml" folder.