Samsung
Remove a Contact Group Member auf Samsung
Contact groups on Samsung phones are meant for sending one message or call to several people at once. If someone no longer belongs in that circle, they stay listed until you actively remove them from the group.
The reason this feels harder than it should is that the group screen only shows members in a read-only view by default. Deleting a name requires switching into an editable state first, otherwise there is no visible option to take anyone out.
To remove a member, go to Tap on Contacts ➔ Open the Menu ➔ Choose a Group ➔ Tap on Edit ➔ Remove the desired Member and tap Save.
This only removes the person from the group. Their contact entry, call history, and message threads with them stay untouched.
If the goal is to stop group messages entirely rather than remove one person, deleting the whole group is faster than editing membership one contact at a time.