Do not touch anything. The progress bar will reach 100% in about 2-3 minutes. The router will automatically reboot.
Standard unlocking methods for the B311-221 are frustrating: huawei router b311221 unlock firmware patched
tftp -i <TFTP_SERVER_IP> get B311-221V2.34.T34 Do not touch anything
If your router still allows code entry, this is the safest and most reliable method. making it unusable.
Improper flashing of firmware can "brick" the device, making it unusable.