Broken Fang Coop Mission - Hard Mode and Coin Locations

CS:GO's new coop mission, set on the map Autumn, contains a secret hard mode activation lever, AND 3 coins. Here's how do find them all.

0:00 - Intro
0:05 - Hard Mode
0:19 - Coin 1
0:32 - Coin 2
0:43 - Coin 3