Starting a conversation with the recipient of an archived discussion automatically unarchives the messages. However, based on your device, if you don’t wish to start chatting but wish to unarchive a conversation, there are other ways of doing so. From an iPhone: 1. Open the Messenger app and select your profile. 2. Tap “Archived Chats.” 3. Swipe to the right and choose the “Unarchive” option on the chat you wish to unarchive. 4. The conversation will now appear in your primary inbox on Messenger. From an Android: 1. From your Home screen, open Messenger. 2. Select your profile at the top of the page and tap “Archived Chats.” 3. Press and hold down the conversation you want to unarchive. 4. From the options that appear, select “Unarchive.” 5. The conversation will now be found in the main Messenger inbox.