ADD & REMOVE USERS IN A GROUP

[root@localhost /]# useradd os1
[root@localhost /]# useradd os2
[root@localhost /]# useradd os3

[root@localhost /]# gpasswd -M os1,os2,os3 soft

[root@localhost /]# grep soft /etc/group
soft:x:504:os1,os2,os3

[root@localhost /]# gpasswd -d os1 soft
Removing user os1 from group soft

[root@localhost /]# grep soft /etc/group
soft:x:504:os2,os3