This wikiHow teaches you how to leave a group message/chat on a Samsung Galaxy device.
Step

Step 1. Open the messaging app or Messages on the Samsung Galaxy device
This app icon looks like three white speech bubbles inside a yellow square on the app menu or main page.

Step 2. Touch the chat group you want to leave
The selected group chat thread will be displayed in the Messages window.

Step 3. Touch the “☰” icon
It's in the upper-right corner of the screen. A new menu will appear on the right side of the screen.

Step 4. Touch the Notifications button
This button looks like an orange bell in the lower-left corner of the quick menu. You will no longer get push notifications from that message group.
-
When selecting the button Notifications ”, the orange bell icon will change to
. This means that notifications from the group have been turned off. After that, you can delete the chat thread.