You can remove members from a Private Group on an Android by completing the following steps:
1. From the private group map, tap the menu icon in the top right of the screen.
2. This will take you the details of your group. Tap on the menu icon and choose Edit Group.
3. Here you can select the member of the group you would like to remove and then tap the trash icon in the top right of the screen.
4. From there, you will be prompted to accept the change with a message asking you if 'you are sure you want to remove these individuals', to which you should select REMOVE.
5. You are then returned to the group details page where you will see the member has been removed.