MAKE SURE YOU CREATE BACKUPS OF YOUR FILES JUST INCASE

Drag and drop mapres.rpf into Red Dead Redemption\game and replace

If you're using a mod that replaces mapres.rpf use an rpf editor such as MagicRDR or Codex to drag and drop smic_player_default_intro_1.wtd and smic_player_default_1.wtd into mapres.rpf