Open Facebook
Go to your Groups list
Select the group you want to leave or delete
If you want to delete the group:
If you’re the group admin, open the group
Tap or click Group settings (or Manage group)
Tap or click Delete group
Confirm deletion when prompted
If you want to remove yourself from the group:
Open the group
Tap or click Joined (or Members)
Tap or click Leave group
Confirm leaving when prompted
If you want to delete multiple posts or comments:
Open your profile
Go to Activity log
Use filters to find posts/comments
Select items to delete
Tap or click Delete
Confirm deletion when prompted
If you want to delete a group conversation/thread:
Open the group
Open the conversation
Tap or click the post/comment options (three dots)
Tap or click Delete
Confirm deletion when prompted