Method 1：

Step 1:

Click「Inbox」，go to Inbox page，find the related chat, go into the chat

Screenshot_315.png

Step 2:

Click X at the top right to delete a tag

Screenshot_316.png

Method 2:

Step 1:

Click「Audience」, go to Audience page，find the related contacts，可參考How to search a contact

Screenshot_317.png

Step 2:

After you find the specific contact, click X at the top right to delete a tag

Screenshot_318.png