Cisco ISE CLI password reset

Hi, all.

Could somebody please explain the best way to reset the the CLI password for SNS-3515 appliance running ISE 2.7?

We've CIMC access but it decided to stop working now. (I can ping but GUI/SSH doesn't work) That leaves me with only option which is via bootable USB. I found this guide but quite confused with the exact steps needed.  steps. https://www.cisco.com/c/en/us/support/docs/security/identity-services-engine/200568-ISE-Password-Recovery-Mechanisms.html

Has anybody done this before? If so, what is the best way to reset it?

Step 3 on the guide says:

Step 3. Restart SNS-35XX appliance and go to the BIOS mode on console

Step 4. In the BIOS mode, choose boot from USB.

Any idea how can I force the ISE to boot to the BIOS? Is there a keyboard break I should send?

Thanks in advance.