What if Redhat forgets the password?

What if Redhat forgets the password?
1. I forgot to install the redhat linux root Password in my VM Virtual router configuration vro vulnerability. I just wanted to reinstall it, but later I thought there was a single mode in linux, using single, you can directly enter the character interface and modify it;
2. Start the vmvm and the linux system;

3. Enter the linux Startup interface and press e to enter the following interface;

4. Press select kernel/vmlinuz-2.4.20-8 ro root = LABEL =/item, press the e key, then "space" input "single ",

5. Press enter after the input is complete;

6. Press the B key to boot and enter the character interface;

7. Enter passwd root to modify the root user password;

8. Enter the new password twice and press enter to display the modification successful;

9. Enter reboot to restart;

10. After restart, use the new password to log on;