In Reaper menu Options > Show REAPER Resource Path
you will see Effects folder and Scripts folder, copy the files and folders the same path in the zip to the same folder path on the hard drive.
Restart Reaper.
Menu Actions>Show Action List>New Action> Load Reascript:
ReaTrak instant trak creator gui (use to set region color).lua
ReaTrak midi chord input to region chord player.lua

Run ReaTrak instant trak creator gui (use to set region color).lua
Run ReaTrak midi chord input to region chord player.lua