Here's how to complete the Hunt for Adler in Warzone limited-time event for rewards and the Tortured and Rescued bonus skin. The event progress is for both Warzone and Coldwar, so either completed task will have to be completed on both games; with Coldwar being free to play this week.
Cold War Challenges
Starting with the three tasks in Call of Duty Cold War, the first intel is Head Comrade Sticker, play and complete 7 games on Yamantau; very simple to do. Next, the Pager charm, eliminate 25 enemies who have been revealed by your Spy Plane, H.A.R.P., or Field Mic to obtain the new charm. Then, the Vengeful Commando calling card, to complete this task is to eliminate 25 enemies on a killstreak while using the Assassin Perk.
The other three tasks to complete in Call of Duty: Warzone, starting with the Rebel Rivas sticker, players simply need to complete the intel contract at Summit. Next, the Close Call charm, this task is to complete an intel at factory. Finally, Missing calling card, complete the intel at Farms.
How to Complete the Hunt for Adler in Warzone
After completing the Hunt for Adler event, players have the possibility of unlocking the Tortured and Rescued bonus skin. By unlocking the bonus operator skin you simply need to complete either three intel pieces for Cold War or Warzone.
For more information check out The Hunt for Adler official post.