Complex sentence: They then had to relay the message to the guard, standing at the monument's entrance, to receive their next clue, where teams had to sign-up and write their arrival time for the Roadblock at Canso X Adventure Park.
Split into simpler sentences: They then had to repeat the message to the guard, standing at the monument's entrance, to obtain their next clue. Then teams had to sign-up and write their arrival time for the Roadblock at Canso X Adventure Park.