How to add members
To add members to an existing group, tap on the group chat → tap on the group name to open profile → tap on Add Members. You can add members even when you are not the initial creator of the group.
How to remove members
To remove member(s), tap on the group chat → tap on the group name → long press the name of the group member you want to remove (Android) → or tap edit on the top right corner → slide left on the group member to delete (iOS).
The removed member and all other group members will be notified that you have removed this member and the removed member will no longer receive notifications from your group. You can remove members even when you are not the initial creator of the group.