How to Remove virbr0 interface in Redhat or Centos ?

by use virsh net-undefine command

This interface is created by libvirtd default network configuration. If you want to only disable this default network use the commands:

virsh net-destroy default

virsh net-autostart default --disable

If you want to remove it, use the comand:

virsh net-undefine default

If you want to disable the libvertd service itself, use the following command for RHEL5 and 6:

chkconfig libvirtd off

For RHEL7:

systemctl disable libvirtd.service