Make sure to first have SuperBLT, and BeardLib installed. Click the links in the dependency list.

Optional video tutorial for installing SuperBLT, BeardLib, and mod_overrides mods: https://youtu.be/rin_sjSJIkg

1. After downloading the mod, use a program such as 7zip or WinRAR to extract the main folder of the mod.
2. Drop that folder into the mods folder which is supposed to be in the game's installation folder (don't know where that is? click here)

FOLLOW INSTRUCTIONS IN THE MAIN DESCRIPTION OF THE MOD.
TLDR: Place in mods, move "CustomOSTTracks" folder into the fixer's folder. Create "CustomOSTTracks" folder there if you didnt have COST before. Remove original "CustomOSTMod" folder.